marine life essay introduction

Introductory essay

Written by the educators who created The Deep Ocean, a brief look at the key facts, tough questions and big ideas in their field. Begin this TED Study with a fascinating read that gives context and clarity to the material.

How inappropriate to call this planet Earth when it is quite clearly Ocean. Arthur C. Clarke

Planet Ocean

In the late 1960s, the Apollo Mission captured images of Earth from space for the very first time. These iconic photos gave people around the world a fresh perspective on our home planet — more specifically, its vast and dazzling expanses of blue. It's perhaps unsurprising that science has subsequently established the key roles that the ocean and its marine organisms play in maintaining a planetary environment suitable for life.

While the Apollo astronauts were sending back pictures of our blue planet, a scientist at the Jet Propulsion Laboratory in California was searching for ways to detect life on other planets such as Mars. James Lovelock's investigations led him to conclude that the only way to explain the atmospheric composition of Earth was that life was manipulating it on a daily basis. In various publications, including his seminal 1979 book Gaia: A New Look at Life on Earth , Lovelock launched the Gaia hypothesis, which describes how the physical and living components of the natural environment, including humankind, interact to maintain conditions on Earth. During the same period, marine scientists including Lawrence Pomeroy, Farooq Azam and Hugh Ducklow were establishing a firm link between the major biogeochemical cycles in the oceans and marine food webs, particularly their microbial components. In the late 1980s and 1990s, large-scale research programs like the Joint Global Ocean Flux Study (JGOFS) explored ocean biogeochemistry and established the oceans' pivotal role in the Earth's carbon cycle.

Research efforts like these underscored the oceans' critical importance in regulating all the major nutrient cycles on Earth. It's now widely recognized that the ocean regulates the temperature of Earth, controls its weather, provides us with oxygen, food and building materials, and even recycles our waste.

The advent of deep-sea science

It seems remarkable that until fairly recently many scientists believed that life was absent in the deep sea. Dredging in the Aegean Sea in the 1840s, marine biologist Edward Forbes found that the abundance of animals declined precipitously with depth. By extrapolation he concluded that the ocean would be azoic (devoid of animal life) below 300 fathoms (~550m depth). Despite evidence to the contrary, scientists supported the azoic hypothesis, reasoning that conditions were so hostile in the deep ocean that life simply could not survive. Extreme pressure, the absence of light and the lack of food were viewed as forming an impenetrable barrier to the survival of deep-sea marine species.

But others were already proving this hypothesis wrong. As Edward Forbes published his results from the Aegean, Captain James Clark Ross and the famous naturalist John Dalton Hooker were exploring the Antarctic in the Royal Navy vessels HMS Terror and HMS Erebus . During this expedition, Ross and Hooker retrieved organisms from sounding leads at depths of up to 1.8km, including urchin spines and other fragments of various marine invertebrates, a number of bryozoans and corals. Ross remarked, "I have no doubt that from however great a depth we may be enabled to bring up the mud and stones of the bed of the ocean we shall find them teeming with animal life." This contention was supported by work of Norwegian marine biologists Michael Sars and George Ossian Sars who dredged hundreds of species from depths of 200 to 300 fathoms off the Norwegian coast.

Further evidence came from natural scientists William Carpenter and Charles Wyville-Thomson, who mounted expeditions in 1868 and 1869 on the vessels HMS Lightening and HMS Porcupine to sample the deep ocean off the British Isles, Spain and the Mediterranean. The findings of these expeditions, which Wyville-Thomson published in his 1873 book The Depths of the Sea , confirmed the existence of animal life to depths of 650 fathoms — including all the marine invertebrate groups — and suggested that oceanic circulation exists in the deep sea.

This convinced the Royal Society of London and the Royal Navy to organize the circumnavigating voyage of HMS Challenger in the 1870s. In part, the expedition's purpose was to survey potential routes for submarine telegraph cables, and so the links between scientific exploration and human use of the deep sea were established in the very early days of oceanography. The Challenger expedition was a watershed for deep-ocean science, establishing the basic patterns of distribution of deep-sea animals, and that their main food source was the rain of organic material from surface waters.

In the 1950s, the Danish Expedition Foundation's Galathea voyage established that life occurred at depths of more than 10km in the Philippines Trench. In 1960 marine explorers Auguste Picard and Don Walsh reached the bottom of the Challenger Deep in the Marianas Trench, at a depth estimated to be 10,916 meters--the deepest part of the ocean — where they observed flatfish from the porthole of their pressure sphere. This feat was not repeated until 2012 when James Cameron visited the bottom of the Challenger Deep in the submersible Deepsea Challenger .

Hype or hyper-diversity in the deep sea?

While working at Woods Hole Oceanographic Institution in the late 1960s, scientists Howard Sanders and Robert Hessler developed new types of deep-sea trawls called epibenthic sleds that featured extra- fine mesh in the nets. When the new trawls were tested, they recovered an astonishing diversity of species from the deep sea. It became apparent that the species richness of deep-sea communities actually increased with greater depth to a peak somewhere on the continental slope between 2,000 and 4,000 meters depth. Beyond these depths, diversity appeared to decrease (but not everywhere), or the pattern was unclear.

How to explain this amazing diversity in the deep sea? Initially, scientists credited the species richness to the stability of environmental conditions in the deep ocean, which would support extreme specialization of the animals and thus allow many species to coexist. This is known as the stability-time hypothesis. Some scientists considered that small-scale variations of the sediments of the deep ocean, including reworking of seabed by animals, was important in maintaining microhabitats for many species. In the late 1970s other scientists suggested that conditions in shallow waters allow competitive exclusion, where relatively few species dominate the ecosystem, whereas in deeper waters environmental factors associated with depth and a reduced food supply promote biological communities with more diversity.

Fred Grassle and Nancy Maciolek added substantially to our knowledge of deep-sea biodiversity when they published a study of the continental slope of the eastern coast of the USA in the early 1990s. Grassle and Maciolek based their study on quantitative samples of deep-sea sediments taken with box cores. These contraptions retrieve a neat cube-shaped chunk of the seabed and bring it to the surface enclosed in a steel box. Scientists then sieve the mud and count and identify the tiny animals living in the sediment.

In a heroic effort, Grassle and Maciolek analyzed 233 box cores, an equivalent of 21 square meters of the seabed, identifying 90,677 specimens and 798 species. They estimated that they found approximately 100 species per 100 km along the seabed they sampled. Extrapolations of this figure suggested that there may be 1 - 10 million macrofaunal species in the deep sea.

What's more, some scientists argued that Grassle and Maciolek's estimates represented only a small part of the species diversity in the ocean depths. Dr John Lambshead of London's Natural History Museum pointed out that Grassle and Maciolek had not examined the smallest animals in sediments — the meiofauna — made up of tiny nematode worms, copepods and other animals. These are at least an order of magnitude more diverse than the macrofauna, suggesting that as many as 100 million species may inhabit the deep ocean.

However, given that the latest approximation of the Earth's biodiversity is 10 million species in total, Lambshead's number appears to be an overestimate. Scientists have since realized that there are major problems with estimating the species richness of large areas of the deep sea based on local samples. Today we understand that species diversity in the deep ocean is high, but we still don't know how many species live in the sediments of the continental slope and abyssal plains. We also don't understand the patterns of their horizontal distribution or the reasons for the parabolic pattern of species diversity as it relates to depth. Evidence suggests, however, that the functioning of deep-sea ecosystems depends on a high diversity of animals — although exactly why remains open to conjecture.

The creation of deep-sea environments: "Drifters" and "Fixists"

In 1912, German scientist Alfred Wegener put forward his theory of continental drift to address many questions that engaged the geologists and biologists of his time. For example, why do the continents appear to fit together as though they had once been joined? Why are many of the large mountain ranges coastal? And, perhaps most intriguing, why do the rocks and fossil biotas (combined plant and animal life) on disconnected land masses appear to be so similar?

Wegener's theory provoked a major scientific controversy that raged for more than 50 years between "drifters" and "fixists." Critics of Wegener's — the "fixists" — pointed out that Wegener's proposed mechanism for drift was flawed.

In the search for an alternate mechanism to explain continental drift, British geologist Arthur Holmes suggested that radioactive elements in the Earth were generating heat and causing convection currents that made the Earth's mantle fluid. Holmes argued that the mantle would then rise up under the continents and split them apart, generating ocean basins and carrying the landmasses along on the horizontally-moving currents.

Following World War II, scientific expeditions employing deep-sea cameras, continuously recording echo-sounders, deep-seismic profilers and magnetometers lent support to the arguments of Holmes and his fellow "drifters." Scientists realized that the deep sea hosted a vast network of mid-ocean ridges located roughly in the center of the ocean basins. These ridges were characterized by fresh pillow lavas, sparse sediment cover, intense seismic activity and anomalously high heat flow. Scientists found geologically-synchronous magnetic reversals in the rocks of the ocean crust moving away from either side of the mid-ocean ridges. Added to this was the fact that nowhere could scientists find sediments older than the Cretaceous in age. Together, these findings suggested that new oceanic crust was being formed along the mid-ocean ridges, while old oceanic plates are forced underneath continental plates and destroyed along the ocean trenches. By the late 1960s, the bitter scientific debate between the "fixists" and the "drifters" was finally settled.

Life without the sun

During the next decade, scientists investigating volcanic activity at mid-ocean ridges became interested in the associated phenomenon of hot springs in the deep sea. Anomalously high temperature readings over mid-ocean ridge axes led scientists to mount an expedition in 1977 to the 2.5 km-deep Galápagos Rift. From the submersible Alvin, the scientists observed plumes of warm water rising from within the pillow lavas on the seabed. Living amongst the pillows were dense communities of large vesicoyid clams, mussels, limpets and giant vestimentiferan tube worms (Siboglinidae). An abundance of bacteria around the Galápagos Rift site immediately suggested that these communities might be based on bacterial chemosynthesis, or chemolithotrophy, using chemical energy obtained by oxidizing hydrogen sulphide to drive carbon fixation. Subsequent investigation confirmed that the giant tube worms, clams and mussels actually hosted symbiotic sulphur-oxidizing bacteria in their tissues.

The discovery caused huge excitement in the scientific community. Here was life thriving in the deep sea, where primary production — the basis of the food web — was independent from the sun's energy. Furthermore, as scientists discovered additional vent communities and surveyed elsewhere in the mid-ocean ridge system, they found that environmental conditions were extreme, with high temperatures, acidic waters, hypoxia (lack of oxygen) and the presence of toxic chemicals the norm.

The implications of this were enormous and went well beyond the study of the ocean itself. First, it meant that life could exist elsewhere in our solar system in environments previously thought too extreme. Second, it widened the potential area for habitable planets around suns elsewhere in the universe. For example, the discovery in 2000 of the Lost City alkaline hydrothermal vents presented an environment that some scientists suggest is analogous to the conditions in which life evolved on Earth.

Subsequently, chemosynthesis has been discovered in many places in the ocean, including deep-sea hydrocarbon seeps, in large falls of organic matter such as whale carcasses, and from shallow-water sediments associated with, for example, seagrass beds.

Drawing down the oceans' natural capital

Over the past two decades, we've developed a much deeper understanding of the relationship between humankind and the natural world, including the Earth's oceans. In 1997 Robert Costanza and his colleagues published a paper in Nature that estimated the economic value of the goods and services provided by global ecosystems. Costanza and his colleagues argued that the living resources of Earth could be viewed as a form of natural capital with a value averaging $33 trillion per annum, upon which the entire human economy depended. These goods and services were later grouped into supporting (e.g. primary production), provisioning (e.g. food), regulating (climate regulation) and cultural (e.g. education) services.

While this knowledge may have been intuitive for many people, Costanza's recasting of the environment in economic terms forced policymakers, industry leaders and others to recognize the importance of long-term environmental sustainability. With the support of international agencies such as the World Bank, many countries are now implementing natural capital accounting procedures through legislation. The purpose of this is to help monitor and regulate the use and degradation of the environment and to ensure that the critical ecosystem goods and services underpinning economic activity and human well-being are not undermined.

Although it seems like a modern preoccupation, sustainability is actually a centuries-old challenge, particularly as it relates to marine environments. For example, there is evidence that aboriginal fisheries in ancient times may have overexploited marine species. Certainly by medieval times in Europe, a thriving market for fish, coupled with other developments like changing agricultural practices, forced species such as salmon and sturgeon into decline.

The Industrial Revolution led to an increase in hunting fish, seals and whales, thanks to the development of steam- and then oil-powered fishing vessels that employed increasingly sophisticated means of catching animals. Pelagic whaling began in the early 20th century; the development of explosive harpoons, the ability to process whales at sea, and the strong demand for margarine made from whale oil all contributed to dramatic rises in catches. Despite the initiation of the International Whaling Commission in 1946, a serial depletion of whale populations took place from the largest, most valuable species (e.g. blue whale) through to the smallest species (minke whale). The failure to regulate catches of whales led to the establishment of a near-moratorium on whaling in 1986.

Over the same post-war period, fishing fleets underwent a major expansion and deployed increasingly powerful fishing vessels. Improved technologies for navigating, finding fish and catching them led to increasing pressure on fish stocks and the marine ecosystems in which they lived. In 1998, after analyzing catch statistics from the United Nations Food and Agricultural Organisation (FAO), Daniel Pauly and his colleagues from the University of British Columbia identified a global shift in fish catches from long-lived, high trophic level predators to short-lived, low trophic level invertebrates and plankton-eating fish. This was the first evidence that fishing was having a global impact on marine ecosystems, causing major changes in the structure of ocean food webs. Aside from the economic impacts of "fishing down the food web," evidence was accumulating that it also affected the vulnerability and/or resilience of marine ecosystems to shocks such as invasions by alien species and climate-change effects such as mass coral bleaching.

Further evidence came in 2003 from a study by Ransom Myers and Boris Worm. Myers and Worm documented a significant decline over time in the stocks of certain large, predatory fish after analyzing information from research trawl surveys and the catches of the Japanese long-line fleet. Other studies over the same time period suggested that sharks, seabirds and turtles were suffering large-scale declines as they became by-catch in many industrial fisheries. Scientists also asserted that some fishing technologies, such as bottom trawling, were extremely damaging to seabed communities — deep-sea ecosystems in particular — by documenting the devastation of cold-water coral communities.

These studies sparked a bitter war of words between marine ecologists, fishing industry executives and fisheries biologists. While it has now been demonstrated that fish stocks can recover if levels of exploitation by fisheries are reduced through management measures, it's clear that in many parts of the world's oceans this is not happening. Overall, global yields from marine capture fisheries are in a downward trajectory. By-catch of some marine predators, such as albatrosses, still poses a threat of extinction. Habitat destruction resulting from fishing is continuing.

In addition to overfishing, other human activities are damaging marine ecosystems. During the 1960s and 1970s, several major accidents with oil tankers and oil installations resulted in serious oil spills. While oil pollution is still a significant problem, as illustrated by the Deepwater Horizon disaster in the Gulf of Mexico in 2010, other less-visible sources of pollution are causing large-scale degradation of the ocean.

Persistent organic pollutants and heavy metals such as mercury are being recognized as major health issues for marine animals (especially high trophic level predators, such as killer whales and tuna) and also for humans. The oceans are becoming the dumping ground for a wide range of chemicals from our personal care products and pharmaceuticals, as well as those that leach out of all manner of plastics that are floating in our seas. Agrochemicals are pouring into the oceans through rivers; in some cases these artificially fertilize coastal waters, generating blooms of algae which are broken down by bacteria, thus stripping the water of oxygen and creating dead zones.

Our release of greenhouse gases into the atmosphere, particularly carbon dioxide (CO2), is leading to a profound disturbance in ocean temperatures and ocean chemistry. Since the late 1970s, mass coral bleaching from ocean warming has killed large areas of tropical coral reefs. Marine animals are changing their distribution and the timing of their lifecycles, sometimes with catastrophic effects across the wider ecosystem. Such effects are often propagated from lower levels of food webs up through to predators such as fish and seabirds: witness recent declines in spectacled sea duck populations in the Arctic and the decline of cod populations in the North Sea. The oceans are becoming more acidic, which affects the growth rates of animals with calcium carbonate shells or skeletons and has other negative impacts on animal physiology. Many of these different stresses on marine species interact in a form of "negative synergy", inducing more severe effects than if they had presented in isolation. At the ecosystem level these stresses reduce the resilience of marine ecosystems to "shocks" arising from large-scale effects, such as anomalous warming events associated with climate change.

Ocean future

The TEDTalks in The Deep Ocean illuminate many current topics in marine science and oceanic exploration. These include the call for better conservation management in the face of unprecedented threats to marine ecosystems, the discovery and application of as-yet-untapped natural resources from the ocean depths, and the quest for improved technologies to support both of these endeavors. As Sylvia Earle eloquently reminds us in her 2009 TEDTalk, the oceans are critically important to maintaining the planet in a condition that is habitable, and better cooperative, international management of marine ecosystems is essential. However, as other TED speakers like Robert Ballard and Craig Venter argue, the oceans should also interest us because they contain vast untapped resources: unexploited mineral resources as well as genes, proteins and other biomolecules of marine life, which may furnish the medicines and industrial materials of the future.

Smart management of these natural resources requires knowledge, as do our efforts to ensure the oceans' ongoing species richness and their critical function in maintaining the Earth system. In their TEDTalks, explorers and scientists Edith Widder, Mike deGruy and Craig Venter share some of the amazing physical and biological features of ocean habitats and describe how new technologies allow more careful study and exploitation of deep-sea environments.

Despite these advances, there are still enormous gaps in our knowledge. In a TEDTalk he gave in 2008, Robert Ballard noted that many parts of the ocean remain entirely unexplored and he advocated for increased resources for organizations like NOAA. As many of the TED speakers in The Deep Ocean argue, marine science is more important than ever because the oceans are under serious threat from a range of human impacts including global-scale climate change.

However, these speakers also offer a message of hope, underscoring that there is still time to alter the current trajectory of degradation. Scientists including TED speaker John Delaney present a vision for the future where ecosystem-based management, coupled with the advent of new technologies that allow us to monitor ocean health in real time, provide us with tools to heal marine ecosystems. This may allow us to restore their capacity to provide goods and services for humankind over the long term. Measures such as marine-protected areas can maintain the oceans' important biogeochemical functions, but will also conserve the remarkable and beautiful marine ecosystems that have culturally enriched the human experience for millennia.

We'll begin our journey into The Deep Ocean with legendary explorer and oceanographer Sylvia Earle, who shares disturbing data about the decline of marine ecosystems and proposes one method to protect what she calls "the blue heart of the planet."

Sylvia Earle

My wish: protect our oceans, relevant talks.

Mike deGruy

Hooked by an octopus.

David Gallo

Underwater astonishments.

Edith Widder

Glowing life in an underwater world.

Robert Ballard

The astonishing hidden world of the deep ocean.

Craig Venter

On the verge of creating synthetic life.

John Delaney

Wiring an interactive ocean.

104 Marine Life Essay Topic Ideas & Examples

🏆 best marine life topic ideas & essay examples, 👍 good essay topics on marine life, ⭐ simple & easy marine life essay titles.

• Marine Degradation and Solutions in the Pacific Region The second issue related to the degradation of marine resources in the Pacific region is the unsustainable use of marine resources, including destructive fishing, which leads to changes in the number and health of species.
• Ocean Pollution and the Fishing Industry In essence, the activities of over six billion people in the world are threatening the survival and quality of water found in the oceans, lakes and other inland water catchment areas. We will write a custom essay specifically for you by our professional experts 808 writers online Learn More
• Ocean Currents: General Information There are generally two types of ocean currents depending on the water level where the movement of oceanic water takes place and they are the deep ocean currents and the surface ocean currents.
• Sea Otters’ Life Cycle From Birth to Death However, after the species had almost become extinct and their protection began, the species began to recover and towards the close of the 20th century, conservation had given rise to tens of thousands of sea […]
• The Ocean Pollution Problem Overview Ocean pollution is the unfavorable upshot due to the entrance of chemicals and particulate substances into the ocean. The land is the key source of ocean pollution in the form of non-point water pollution.
• Climate Change Impacts on Ocean Life The destruction of the ozone layer has led to the exposure of the earth to harmful radiation from the sun. The rising temperatures in the oceans hinder the upward flow of nutrients from the seabed […]
• Living Resources of the Ocean The most commendable among the benefits of marine life to human life are the fact that marine life can act as food and the fact that some oceanic organisms have medicinal value.
• The Problem of Ocean Pollution in Modern World Wastes such as toxic matter, plastics, and human wastes are some of the major sources of pollution in the ocean. Many people consume fish as food; when marine life is affected by toxic substance in […]
• Deep Sea Volcanoes and their Effects Deep sea volcanoes are present under deep sea ridges of the ocean floor and the above research has been based on the amount of carbon dioxide that is present in depths of four kilometers on […]
• High Seas Marine Protected Areas: Effective Legislation or Paper Parks This essay dwells on the definition and importance of MPAs, including the ones in the high sea. The goal of the alliance is to bolster international collaboration and exchange of knowledge.
• The Impacts of Oil Spills on Marine Life The intensity of aquatic effects is influenced by the nature and extent of the spilt oil. Besides, the severity might be influenced by the sensitivity and ambient state of the pretentious marine and their surroundings […]
• Marine Surveying, Inspection and Safety Practices The importance of these conventions and rules was to address the need to access different ports in different countries based on uniform rules and standards acceptable to destination ports or countries in addition to maintaining […]
• Life in the Bottom of the Ocean and Its Protection While we all strive hard to detect and analyze the essence of life and the impact it has on our lives, we need to understand that life in itself is a big mystery, the truth […]
• Plastic Waste and Its Effects on Marine Life However, many people do not appreciate the importance of oceans to human and marine life. Another effect of microplastics on the marine community is that they lead to uneven distribution of organisms.
• The Aral Sea Problems, Their Causes and Consequences To identify and analyze the problems of the lake, its basin, and the entire region To discuss the causes and consequences of the lake’s destruction To evaluate the solutions proposed for ameliorating the consequences The […]
• Non-trophic Interaction in Marine Species An example of non-trophic relationships between marine species is decorator crabs and sponges. Decorator crabs and sponges’ relations are an example of mutually helpful non-trophic interaction mutualism.
• The Rising of Sea Level and Melting Glaciers: Analysis of the Issues In modern realities, the rate of warming of the World’s Oceans has increased. Global warming provokes the melting of ice in Greenland and Antarctica.
• Deep-Sea Currents and Upwelling Along Florida The thermohaline circulation influences the movement and population of the marine ecosystem and heat redistribution both in the sea and on the earth’s surface.
• The Aral Sea’s Environmental Issues Prior to its destruction, the Sea was one of the biggest water bodies, rich in different species of flora and fauna; a case that is opposite today, as the sea is almost becoming extinct.
• The Indian Ocean Tsunami of 2004 and Its Consequences The worst effects of the great wave were observed in Indonesia, where the death toll exceeded 160,000 people, and the overall damages almost reached $4.
• Marine Life in United Arab Emirates This report analyses the marine life in the UAE, covering detailed information about the various species of animals found in the region and their adaptation to the unique environment.
• Marine Parks Concept Overview In terms of marine tourism, aquatic parks offer the best solution for tourists because they are cheaper than watching animals in the sea.
• The Global Ocean Conveyor Belt This ocean water phenomenon is a result of the temperature difference in the ocean waters between the warm, salty surface water, and the less salty cold water in the ocean depths.
• Policy Change to Control Ocean Dumping Policies addressing the issue of ocean dumping and the need to curb it have been in place. Several factors fueled the change; for instance, change in the information concerning the effect of ocean dumping to […]
• Ocean Dumping Issue and Rhetorical Rationale Therefore, the goal of this paper is to prove that the poster in question manages to accomplish an impressive goal of subverting the audience’s expectation and encouraging them to shift from an ironic perception of […]
• The Negatives of Fossil Fuel: Ocean Acidification and Human Health The adverse effects of burning oil are hard to overestimate. Unless specific and practical actions are taken to address the issues of global climate change and pollution issues and reduce reliance on oil, the future […]
• Impacts of Climate Change on Ocean The development of phytoplankton is sensitive to the temperature of the ocean. Some marine life is leaving the ocean due to the rising water temperature.
• Exploring Environmental Issues: Marine Ecotourism For marine ecotourism to succeed, it must thrive in a manner that accommodates the needs of both the current and future generations and safeguards the natural environment.
• Autonomous Platforms in Marine Research One of the significant ideas that can increase the overall efficiency of the data collection process is the creation of networks of autonomous platforms.
• The Sea Water Impact on the Human Cell Hence, consuming it causes a high amount of salt without the human cell, which leads to a steep concentration gradient within the cell, thereby causing water to be drawn out, which is detrimental to the […]
• Ocean Sustainability and Human Economic Activity The world economy and the livelihoods of hundreds of millions of people depend on the ocean. It is important to remember that the misuse of water resources and the effects of global climate change will […]
• Integrated Coastal Zone Management in the Red Sea and the Gulf of Aden The role of the ICZM in the control of environmental, transport, industrial, and other types of safety is high, and the example of the RSGA region proves this.
• Mining and Ocean Use in Canada Cobalt, nickel, manganese, and copper are among the metals deep seabed mining seeks to extract from the polymetallic nodules on the seafloor and seamounts.
• Addressing Marine Debris: Causes, Effects, and Potential Solutions A major limitation that makes the eradication of the problem difficult is the fact that most of the debris contains microplastic.
• Sea Foods in the Environment Protection Context Further, the purpose of the website is to give information that seeks to reward the efforts of people who protect and safeguard the ocean and seafood supplies such as lobsters.
• How Deep Sea Discoveries Inspires Professional Creativity Limited technological access to the deep seas should inspire one to focus on the necessary technology to build the most efficient deep-sea robots.
• Visiting San Francisco Bay as Marine Protected Area San Francisco Bay Bridge will become the central place for this trip because it is just in the center of this view.
• Habitat and Ocean Life Considerations of Bottlenose Dolphins The temperate and tropical oceans of the world are home to bottlenose dolphins. On the American continent, bottlenose dolphins can be seen along California’s southern beaches and the eastern seaboard from Massachusetts to Florida, and […]
• The Ocean Dumping Problem: A Visual Argument There is, however, less awareness of deep-sea drilling and the impacts on the habitat and human life in the oceans and along the coasts.
• Australia’s Endangered Diverse Marine Ecosystem Climate Change and population increase are becoming increasingly difficult to perceive distinctly, especially when the question is about the loss of a diverse marine environment.
• Marine Environment Protection and Management in the Shipping Industry Therefore, criminal penalties system in collaboration with the Environmental Protection Agency should reinforce legislations to protect sea creatures and humans from oil pollution or wastes from ships.
• Marine Creatures and Terrestrial Animals in “The Wild West: Gold Rush” In fact, Californian nature is rich in various animal species that live to survive and pass their genes to the offspring.
• Integrated Ocean Drilling Program Expedition 342 Such flows reduce the temperature of the planet’s core, change the composition of the foundation bedrock, and impact microorganism dispersion in the subterranean ecosystem.
• Ocean Circulation and Biogeography, Species Distribution, Invasive Species The concept of ocean circulation refers to the movements of water in the oceans and seas. Surface ocean currents carry water from the poles to the tropics, where it is heated, and, afterwards, this water […]
• “History of Ocean Basins” by Hess From the article it is vivid that the coming into being of oceans is subject to discussion since the previous knowledge is doubtful, and the existing framework is confusing.
• Plastic Ocean and Its Effect on the Ecosystem The purpose of this essay is to present science-based facts in support of the author’s words to convince the reader of the criticality of the ecological problem.
• Marine Protected Areas: Impact on Kelp Forest Recovery and Urchin Reduction The research aims to study the effectiveness of MPA for kelp forest recovery and urchin reduction. The research aims to study the effectiveness of MPA for kelp forest recovery and urchin reduction.
• Environmental Marine Ecosystems: Biological Invasions One of the biggest hypoxic zones in the US is in the Gulf of Mexico. The condition of water in the area caused the decline of the shrimp industry.
• Effect of Sea Water and Corrosion on Concrete On the other hand, substantial tautness, for instance due to meandering will shatter the tiny firm pattern, ending up in fracturing and disjointing of the concrete.
• How the Ocean Current Affect Animals’ Life in the Sea Depending on the strength of the ocean current, sea animals along the path are flown along with the water, and the animals are moved to new regions that are sometimes thousands of kilometers away causing […]
• Effects of Global Warming on Marine Life Global warming has adverse effects on the marine life. It has led to the extinction of some of the animals and living things and has been necessitated by human activities.
• Deep-Sea Biology: The Search for a Sea Monster This case study is about the attempts of Clyde Roper to find the giant squid. This canyon is known to be very deep and runs towards the Kermadec Trench which is also documented to be […]
• Bacterial Diseases of Marine Organisms The striped dolphin is a highly susceptible host of the bacteria and poses and the most potent reservoir and source of transmission of the infectious agent.
• Ecotoxicology: Toxic Wastes in the Marmara Sea The importance and actuality of the paper can not be exaggerated, as the problem of toxic wastes is one of the most burning in Europe.
• How Climate Change Impacts Ocean Temperature and Marine Life The ocean’s surface consumes the excess heat from the air, which leads to significant issues in all of the planet’s ecosystems.
• Dell’s Initiative to Recycle Ocean-Bound Plastics The innovation to use plastics from the ocean and areas where these materials had a high risk of moving to the water was presented to the company in 2015.
• Intergovernmental Relations and Ocean Policy Change The administration of Ronald Reagan contributed to the Federal ocean policy in the 1980s. During this change, analysts believed the United States was making a shift from ocean protection of the 1970s to ocean management […]
• Improving the Response to Marine Emergencies However, we still need to facilitate this process, for instance, by informing the National Fire Service about the implementation of this project and its results. These are the most objectives that have to be attained […]
• A Benchmarking Biodiversity Survey of the Inter-Tidal Zone at Goat Island Bay, Leigh Marine Laboratory Within each quadrant, the common species were counted or, in the case of seaweed and moss, proliferation estimated as a percentage of the quadrant occupied.
• Ocean Circulation in a Warming Climate These effects will enhance the development of reduced release of radio-carbon depleted carbon dioxide gas and thus the idea of the self-restoration mechanism of the earth to this global warming.
• Protected Marine Areas: Great Barrier Reef To protect the Great Barrier Reef the administration has put in place several policies to protect this region. In this plan, A panel of scientists was to advise on the quality of waste.
• Ocean Thermal Energy Conversion The warm seawater is carried into a chamber and is used to produce vapor that, in turn, is used to rotate a turbine.
• Review of the Quaternary History of Reefs in the Red Sea With Reference to Past Sea-Level Changes Some of the changes have occurred on the very grandest of scales, such as the Merging and ensuing breaking up of huge supercontinents, or the decimation of the dinosaurs by extra-terrestrial impacts.reefs are not invulnerable […]
• Radiocarbon C14 Dating in Marine Geology The radiocarbon technique can say to be one of the most important inventions of the 20th century, especially in the field of human science.
• Marine Biology: Polar Oceans as an Eco System The water in and around the Antarctic continent is referred to as the Antarctic or Southern Ocean. The Atlantic Water is situated between the Arctic Surface Water and the Arctic Deep Water.
• Marine Pollution: Management and International Legislation Marine environment refers to: the physical, chemical, geological and biological components, conditions and factors which interact and determine the productivity of, state, condition and quality of the marine ecosystem, the waters of the seas and […]
• Marine Pollution: Sources, Types, Pathways, and Status By examining sources, types, pathways, and status of water contamination in the context of the World Ocean, it is clear that most marine pollution caused by human actions, especially the mismanagement of plastic debris.
• Concerns of Ocean Ecosystem Pollution The range of adverse outcomes for ocean ecosystems can be discussed in volumes; however, the current discussion will focus on trash in the ocean waters, acidification, and the disruption of the marine life cycles.
• Hudson River’s Ocean Floor Investigation Mapping the ocean floor of the Hudson River would enable the analysis of sediments and the bottom surface hardness as well as would provide data on bottom features and the depth of the river.
• Port Philip Bay and Sea Levels in Australia’s Geological History As the scientist explains, the phenomenon of the port’s emergence in the dry environment can be attributed to the fact that considerable water shrinkage could be observed in the area roughly 1,000 years ago.
• Geology: Port Phillip Bay and Sea Level Changes Specifically, the fossils of specific creatures, such as the shells of tertiary foraminifera, as well as the meanders of the river channels, which were located in the area, are bound to bolster the hypothesis suggested […]
• Marine Algae Associated Bacteria as Antioxidants The antinociceptive activity analysis involved comparing the reaction time of mice treated with the extracts and the controls. The authors conclude that the isolation and characterization of the bioactive principles from the potent strains could […]
• Ocean-Plate Tectonics and Geology Bathymetry of the ocean seafloor refers to the measurement of how deep the sea is in relation to the sea level.
• “Manifest Destiny”: Westward Expansion to the Pacific Ocean The concept of Manifest Destiny elucidates the states of mind of many expansionist principle makers of the period who worked hard in an attempt to push America’s borders towards the west.
• Impact of Sea Transport on the Aquatic Environment The shipping companies also have a serious impact on the maritime environment in terms of the wastes often released into the water.
• Climate Change Effects on Ocean Acidification The scientists realized that the crisis lasted for several millennia before the oceans could fully recover from the impacts of the drop in the pH level.
• Marine Geology, Hydrology and Human Impact on Earth However, the implementation of the new technologies and practices in the process of investigation of the sea depths resulted in the appearance of the new meaning.
• Marine Ecosystems, Human Dependence and Impact The growth of communities dependent on fishing is proportional to the destruction of marine ecosystems. The survival of the human race, and the survival of millions of species of wildlife is dependent on a healthy […]
• The Northern Sea Route’ Safety Management The company discusses the opportunity to trade some of the vessels with the help of the NSR. The NSR is discussed as an attractive option to decrease the time spent in the voyage while comparing […]
• Water Crisis, Oceans and Sea Turtles Issues In the case of Mexico, it appears that the past regimes have never put a lot of focus on the utilization of water resources.
• National Marine Fishery Service Business Projects Within a fishery management context, the report primarily focuses on the provisions of the Magnuson-Steven Fishery Conservation and Management Reauthorization Act issues in 2006.
• The Dead Sea Geochemical History Globally, the most saline location is found on the water surfaces and shores of the Dead Sea. On the other hand, the pattern of fluctuation in temperature and salinity in the Arctic Ocean is complex.
• SOFAR Effects on the Marine Life The speed and energy of the sounds that are transmitted in the SOFAR channel are maintained without being altered because of the pressure, which increases with increase in depth.
• Ocean Acidification Impact on the Sea Urchin Larval Growth Due to the carbon dioxide increase in the atmosphere, acidity in the oceans is increasing++ and a fast increase of change rate is experienced.
• Deep Sea Mining: Salt Extraction This therefore shows how important the process of evaporation is in regard to extraction of salt from the sea. This therefore explains that sea water is a cheap source of salt in terms of time […]
• Pacific Ocean: Essentials of Oceanography The ocean has about 25,000 islands which are in excess of the entire number islands in all the oceans across the world. The volume of water in the ocean is about 622 million km3.
• Marine Pollution and the Anthropogenic Effects Upon It Marine pollution denotes the introduction of harmful materials or chemicals in our oceans which may disrupt the marine ecosystem, cause other harmful effects to marine life or change the chemical properties of the water.
• Marine Biodiversity Conservation and Impure Public Goods The fact that the issue concerning the global marine biodiversity and the effects that impure public goods may possibly have on these rates can lead to the development of a range of externalities that should […]
• El Niño’s Effects on Marine Life El Nino makes the winds of the east blow to the west and moves the layers of warm water in the Pacific Ocean.
• Marine Ecosystems in Oceanography Studies While oceanography students need to understand these aspects of ocean management, this paper focused on marine ecosystems, as a broad and useful topic in oceanography studies.
• Ocean Acidification: Marine Calcification Process This article correlates calcium with oceanography because the process of acidification, which causes the ocean’s pH to decrease because of excess carbon from the atmosphere, has impacts on calcifying organisms in the oceans.
• Ecology Issues: Creatures of the Deep Sea Discuss the negative changes that are occurring and the cause of these changes In the recent past, the temperature on the earth has been rising steadily due to the effect of global warming.
• Ocean Literacy and Exploration From the onset of “human-ocean interaction and exploration in the fifteenth century” and despite ocean being the largest feature of the earth, only 5% of the ocean is known.
• Ocean and Atmosphere Circulation Oceanic and atmospheric circulation is the means by which heat is distributed on the surface of the Earth by large scale circulation of air.
• The Role of Sea Power in International Trade The historical influence that the marines or the navy has had on international trade and the complications in comparing measures of sea power has been issues of discussion in the past.
• Ocean Fisheries Sustainability Analysis It is necessary for fishing industries to use better fishing methods in the ocean to ensure that their activities do not endanger the ecological balance. Fish species do not get the chance to replenish and […]
• Florida Keys National Marine Sanctuary Reefs This essay addresses some of the disturbances which have been experienced in the coral reefs of the Florida Keys National Marine Sanctuary together with measures which have been implemented to salvage the ecosystem.
• Marine Conservation and Coastal Development The committee should comprise of a balanced membership for holistic review of the coastal development projects. The lack of legislation related to marine conservation is also a major setback.
• Plastic Ocean Pollution on Ocean Life in U.S. Ocean plastic pollution has had a great impact on a minimum of two hundred and sixty seven species across the world and these include forty three percent of all of the sea mammal species, eighty […]
• Impact of the Toxic Substances on Marine Ecosystem The condition of hypoxia is created when algal biomass decompose leading to dissolution of oxygen in the water column. While, on the other hand, farming of Bluefin tuna leads to destruction of marine life as […]
• Climate Shift Could Leave Some Marine Species Homeless This is very important as it helps put pressure on countries to reduce on carbon release, in order to conserve the environment and hence species at risk.
• The Difficulties in Exploiting Sea Floor Massive Sulfide Deposits However, the difficulties involved in exploring the minerals have been the greatest obstacles to the full exploration of sea floor mineral deposits such as sulphide. The regulatory environment is the other issue of concern in […]
• Global Warming Outcomes and Sea-Level Changes The outcome of global warming has been exhibited by the melting of ice and snows in areas such as the Antarctic which has changed the average sea level of the whole world because the ice […]
• The Ocean’s Rarest Mammal Vaquita – An Endangered Species The vaquita looks like a curved stocky porpoise, and it is the smallest of all the porpoises in the world. This is a matter of concern and ought to be investigated if the survival of […]
• Chicago (A-D)
• Chicago (N-B)

IvyPanda. (2024, February 29). 104 Marine Life Essay Topic Ideas & Examples. https://ivypanda.com/essays/topic/marine-life-essay-topics/

"104 Marine Life Essay Topic Ideas & Examples." IvyPanda , 29 Feb. 2024, ivypanda.com/essays/topic/marine-life-essay-topics/.

IvyPanda . (2024) '104 Marine Life Essay Topic Ideas & Examples'. 29 February.

IvyPanda . 2024. "104 Marine Life Essay Topic Ideas & Examples." February 29, 2024. https://ivypanda.com/essays/topic/marine-life-essay-topics/.

1. IvyPanda . "104 Marine Life Essay Topic Ideas & Examples." February 29, 2024. https://ivypanda.com/essays/topic/marine-life-essay-topics/.

Bibliography

IvyPanda . "104 Marine Life Essay Topic Ideas & Examples." February 29, 2024. https://ivypanda.com/essays/topic/marine-life-essay-topics/.

• Noise Pollution Essay Titles
• Ocean Pollution Titles
• Water Pollution Research Topics
• Oceanography Research Ideas
• Wildlife Ideas
• Zoo Research Ideas
• Ocean Research Ideas
• Coral Reef Essay Topics
• Hunting Questions
• Moby Dick Questions
• Landfill Essay Titles
• Pollution Essay Ideas
• Tsunami Essay Ideas
• Biodiversity Research Topics
• Fishing Research Topics

An official website of the United States government

Official websites use .gov A .gov website belongs to an official government organization in the United States.

• Education home
• About NOAA Education
• NOAA in your backyard: Alaska
• NOAA in your backyard: Caribbean
• NOAA in your backyard: Central
• NOAA in your backyard: Great Lakes
• NOAA in your backyard: Gulf of Mexico
• NOAA in your backyard: Mid-Atlantic
• NOAA in your backyard: Northeast
• NOAA in your backyard: Northwest
• NOAA in your backyard: Pacific Islands
• NOAA in your backyard: Southeast
• NOAA in your backyard: Southwest
• Educational mailing lists
• Oct-Dec 2023
• Jul-Sep 2023
• Apr-Jun 2023
• Jan-Mar 2023
• NOAA Sea to Sky: Education resource database
• Ocean acidification
• Ocean currents
• Ocean floor features
• Ocean pollution and marine debris
• El Niño and La Niña
• Space weather
• Weather observations
• Weather systems & patterns
• Carbon cycle
• Changing seasons
• Climate change impacts
• Climate data monitoring
• Aquatic food webs
• Coral reef ecosystems
• Fisheries and seafood
• Life in an estuary
• Marine mammals
• Sea turtles
• Great Lakes ecoregion
• Water cycle
• Watersheds, flooding, and pollution
• Data resources for educators
• Education at home
• Elementary resources
• Hands-on science activities
• Special topics
• Conference resources
• About the education resource collections
• Conservation Service Corp Act Direct Hiring Authority
• Educator opportunities
• Grants & networks
• News and stories

Marine life

Our ocean, coasts, and estuaries are home to diverse living things. These organisms take many forms, from the tiniest single-celled plankton to the largest animal on Earth, the blue whale. Understanding the life cycles, habits, habitats, and inter-relationships of marine life contributes to our understanding of the planet as a whole. Human influences and reliance on these species, as well as changing environmental conditions, will determine the future health of these marine inhabitants. Toxic spills , oxygen-depleted dead zones, marine debris , increasing ocean temperatures, overfishing, and shoreline development are daily threats to marine life. Part of NOAA's mission is to help protect these organisms and their habitats.

Food webs describe who eats whom in an ecological community. Made of interconnected food chains, food webs help us understand how changes to ecosystems — say, removing a top predator or adding nutrients — affect many different species, both directly and indirectly.

Phytoplankton and algae form the bases of aquatic food webs. They are eaten by primary consumers like zooplankton, small fish, and crustaceans. Primary consumers are in turn eaten by fish, small sharks, corals, and baleen whales. Top ocean predators include large sharks, billfish, dolphins, toothed whales, and large seals. Humans consume aquatic life from every section of this food web.

Coral reefs are some of the most diverse ecosystems in the world. Coral polyps , the animals primarily responsible for building reefs, can take many forms: large reef building colonies, graceful flowing fans, and even small, solitary organisms. Thousands of species of corals have been discovered; some live in warm, shallow, tropical seas and others in the cold, dark depths of the ocean.

Seafood plays an essential role in feeding the world’s growing population. Healthy fish populations lead to healthy oceans and it's our responsibility to be a part of the solution. The resilience of our marine ecosystems and coastal communities depend on sustainable fisheries.

Estuaries are areas of water and shoreline where rivers meet the ocean or another large body of water, such as one of the Great Lakes. Organisms that live in estuaries must be adapted to these dynamic environments, where there are variations in water chemistry including salinity, as well as physical changes like the rise and fall of tides. Despite these challenges, estuaries are also very productive ecosystems. They receive nutrients from both bodies of water and can support a variety of life. Because of their access to food, water, and shipping routes, people often live near estuaries and can impact the health of the ecosystem.

Marine mammals are found in marine ecosystems around the globe. They are a diverse group of mammals with unique physical adaptations that allow them to thrive in the marine environment with extreme temperatures, depths, pressure, and darkness. Marine mammals are classified into four different taxonomic groups: cetaceans (whales, dolphins, and porpoises), pinnipeds (seals, sea lions, and walruses), sirenians (manatees and dugongs), and marine fissipeds (polar bears and sea otters).

Sea turtles breathe air, like all reptiles, and have streamlined bodies with large flippers. They are well adapted to life in the ocean and inhabit tropical and subtropical ocean waters around the world. Of the seven species of sea turtles, six are found in U.S. waters; these include the green, hawksbill, Kemp's ridley, leatherback, loggerhead, and olive ridley.

Presentations made painless

• Get Premium

112 Marine Life Essay Topic Ideas & Examples

Inside This Article

Marine life is a fascinating and diverse world that captivates the imagination of many. From the colorful coral reefs to the mysterious depths of the ocean, there is no shortage of topics to explore when it comes to marine life. In this article, we will provide 112 marine life essay topic ideas and examples to inspire your next writing project.

• The impact of climate change on marine life
• The importance of coral reefs in marine ecosystems
• The threat of plastic pollution to marine animals
• The role of marine protected areas in conservation efforts
• The fascinating world of deep-sea creatures
• The relationship between marine mammals and humans
• The conservation status of endangered marine species
• The effects of overfishing on marine populations
• The role of marine bacteria in nutrient cycling
• The evolution of marine life over millions of years
• The symbiotic relationships between marine organisms
• The impact of ocean acidification on marine ecosystems
• The role of marine plants in producing oxygen
• The dynamics of marine food webs
• The adaptations of marine animals to their environment
• The importance of mangrove forests in coastal ecosystems
• The threats facing sea turtles in the wild
• The role of marine predators in controlling prey populations
• The diversity of marine life in different ocean regions
• The relationship between climate change and coral bleaching
• The behavior of dolphins in the wild
• The conservation efforts to protect whale populations
• The role of marine invertebrates in marine ecosystems
• The impact of noise pollution on marine mammals
• The economic value of marine resources
• The effects of ocean currents on marine life distribution
• The role of marine fungi in marine ecosystems
• The impact of oil spills on marine habitats
• The adaptations of deep-sea creatures to extreme conditions
• The role of marine viruses in marine ecosystems
• The threats facing shark populations in the wild
• The conservation status of seahorses in the wild
• The role of marine birds in marine ecosystems
• The impact of microplastics on marine organisms
• The adaptations of polar marine animals to cold temperatures
• The relationship between marine animals and their environment
• The diversity of marine species in coral reefs
• The threats facing coral reefs in the wild
• The impact of ocean pollution on marine habitats
• The adaptations of marine animals to changing ocean conditions
• The relationship between marine animals and their predators
• The importance of marine biodiversity in ecosystem health
• The impact of overfishing on marine ecosystems
• The adaptations of marine animals to extreme temperatures
• The relationship between marine animals and their prey
• The importance of marine protected areas in conservation efforts
• The threats facing marine mammals in the wild
• The impact of climate change on marine ecosystems
• The impact of overfishing on marine populations

These 112 marine life essay topic ideas and examples cover a wide range of fascinating and important subjects related to marine life. Whether you are interested in the conservation of endangered species, the impact of human activities on marine ecosystems, or the adaptations of marine animals to their environment, there is no shortage of topics to explore. So pick a topic that interests you, do some research, and start writing about the wonders of the marine world.

Want to create a presentation now?

Instantly Create A Deck

Let PitchGrade do this for me

Hassle Free

We will create your text and designs for you. Sit back and relax while we do the work.

Explore More Content

• Privacy Policy
• Terms of Service

© 2023 Pitchgrade

Bringing the Ocean Back: An Introduction to Ocean Conservation

In this overview of ocean science and the Pristine Seas initiative, students can learn how the ocean works, what we’ve done to it, and how to bring it back.

Biology, Conservation, Oceanography

Loading ...

National geographic | pristine seas.

This resource is provided in both English and Spanish. Scroll down for the Spanish edition.

Introduction

When I was a kid growing up in the Mediterranean, I was fascinated by the life I saw in shallow waters: algae, anemone, little crabs and small fish. But I never saw anything large—until I obtained my scuba diving license and dived in a fully protected marine reserve. I remember that first dive vividly. The big fish missing from the sea of my childhood were there: groupers, sea bream, seabass ... It took many years of education for me to learn how the ocean works, what we’ve done to it, and how to bring it back. I hope this handbook will provide a good introduction I wish I had when I was a kid wanting to be part of the sea.

-Enric Sala National Geographic Explorer in Residence

Three lives have I. Wet enough to quench your thirst, Light enough to touch the sky, Hard enough to break down rock. What am I?

Water is the only substance on Earth that naturally occurs in three physical states: solid, liquid, and gas. It is our planet’s defining feature. Most of our water is found in the ocean. Water also exists as a solid in ice caps and as a vapor in the air. Earth is a closed system. Its water is finite. That means the amount of water in, on, and above our planet does not increase or decrease. Instead, it flows endlessly between the ocean, atmosphere, and land in a system we call the water cycle .

Most of our Earth is covered by water: 29 percent land, 71 percent water.

Most of our water is saltwater: 97 percent salt water, 3 percent freshwater.

Only a small portion of Earth's water is accessible to people: 0.3 percent accessible, 99.7 percent stored in the ocean, soil, ice caps, and in the atmosphere.

While there is only one global ocean, the vast body of water that covers our planet is geographically divided into distinct, named regions. The boundaries of these have evolved over time for historical, cultural, geographical, and scientific reasons. You may know these regions as the Atlantic, Pacific, Indian, and Arctic. Not long ago, the Southern Ocean, which encircles Antarctica, joined the list. All of these basins are connected and exchange water as part of a single world ocean.

Each ocean basin is made up of the seafloor and all of its geological features, such as trenches, islands, ridges, volcanoes, and seamounts. Each basin varies in size, shape, and features due to the movement of Earth’s crust. Some of Earth’s highest peaks, deepest valleys, and flattest plains are found underwater.

Ocean in Motion

The ocean is never still. Both quick-moving surface currents and slower-moving deep ocean currents circulate water around the globe. Surface currents are mostly driven by wind and Earth’s rotation. Deeper ocean currents are controlled by temperature and salinity . That’s because both heat and salt influence the density of seawater. Saltier water is more dense than freshwater. Cold water is denser than warm water. Denser water sinks.

Ocean water always moves toward equilibrium, or balance. For example, if surface water cools and becomes denser, it will sink. The warmer water below will rise to balance out the missing surface water.

Ocean currents move a lot like a conveyor belt that delivers luggage at an airport. The ocean doesn’t move as fast as luggage, though. Scientists estimate that it takes the ocean conveyor belt about 1,000 years to make one trip around the world.

This conveyor belt helps keep our planet warm. When sunlight reaches Earth’s surface, the ocean absorbs some of this energy and stores it as heat. Ocean currents help move heat around the world. For example, warmer, surface water from the Equator moves toward the poles, and colder, deep water from the poles moves back to the tropics. Without this exchange, it would be even hotter at the Equator and colder toward the poles, and much less of our planet would be habitable.

As we know, increasing greenhouse gas concentrations are trapping more energy from the sun in Earth’s atmosphere. Water has a much higher heat capacity than air, meaning the ocean can absorb larger amounts of heat energy with only a slight increase in temperature. As such, our ocean has absorbed more than 90 percent of Earth’s extra heat since 1955.

Ocean temperature plays an important role in Earth’s climate system, too, because heat from ocean surface waters provides energy for storms. As our climate warms, we’re experiencing stronger winds, higher storm surges, and record rainfalls—which is also why these storms are becoming more destructive and costly.

You may be familiar with the terms climate and weather. Climate is how the weather usually is over the whole year in a particular place. Weather is the short-term atmospheric conditions of a place. Here’s one way to think about it. What’s in your closet? Weather is how you decide what you’re going to wear today. Climate is how you decide what kind of clothes you have in your entire closet.

Earth’s Lungs

You may have heard Earth’s rainforests sometimes described as a lung because they draw in carbon dioxide and expel oxygen. But just like most of us, Earth has two lungs. The ocean is its second lung.

The ocean relies on tiny, single-celled organisms called phytoplankton . Though a phytoplankton cell is smaller than the width of a human hair, there are a billion billion billion phytoplankton in the ocean, and they are some of Earth’s most critical organisms. Phytoplankton generate about half of our planet’s oxygen—as much per year as all land plants.

Through photosynthesis, phytoplankton consume carbon dioxide and expel oxygen. Some of the carbon is carried to the deep ocean when phytoplankton die and sink. This removes greenhouse gases from the atmosphere in a process known as carbon sequestration . The ocean stores 50 times more carbon dioxide than our atmosphere, and the top floor of the sediment on the seafloor stores twice more carbon that the soils of the land.

Some carbon is transferred to different layers of the ocean as phytoplankton are eaten by other creatures. Phytoplankton are the foundation of virtually every aquatic food web. They are eaten by everything from microscopic, animal-like zooplankton to massive whales.

Biodiversity

You may have heard that the ocean has the greatest biodiversity on our planet. Marine biodiversity refers to the variety of what lives in our ocean—all the animals, plants, and microorganisms. While that might sound simple, biodiversity is a fairly complex concept and can be measured in several ways.

Species Diversity (also called Species Richness ) refers to the number of species in a place. A place might have many different species of fish, for example.

Genetic Diversity is the range of inherited traits within a species. If a population consists of individuals with a wide variety of different traits, it may have high genetic diversity.

Functional Diversity reflects the ecological complexity of an ecosystem. Many organisms with different roles in the food web would indicate a high level of functional diversity.

We know that each species is an integral part of its ecosystem, and it performs functions that are essential to that ecosystem. Here’s an example: Hard corals grow by forming skeletons made of limestone, which over the centuries, build coral reefs. Those reefs will act as a barrier that protects coral islands and atolls and provide habitat for many species of fish. Here are some other functions species might provide in an ecosystem:

• Produce oxygen
• Produce organic material
• Decompose organic material
• Cycle water and nutrients
• Control erosion or pests
• Help regulate climate and atmospheric gases

Removing species from ecosystems removes these important functions. Therefore, the greater the diversity of an ecosystem, the better it can maintain balance and productivity and withstand environmental stressors. Biodiversity means that our ocean can be productive, resilient, and adaptable to any environmental changes. We say an ecological system is resilient if it can bounce back after a disturbance hits it—for example, a coral reef coming back after an ocean warming event kills some of its corals.

Biodiversity has intrinsic value because all species:

• Provide value beyond their economic, scientific, and ecological contributions
• Are part of our cultural and spiritual heritage
• Are valuable for their beauty and individuality
• Have a right to life on this planet

Biodiversity is critically important to us in terms of:

• Food resources
• Biomedical research
• Tourism and recreation

Food Resources

Fish are crucial to a nutritious diet in many areas across the world, especially among coastal communities. Fish provide about 3.3 billion people with almost 20 percent of their intake of animal protein. Global fish consumption increased 122 percent between 1990 and 2018, and that figure is expected to rise in the future.

We use our ocean as a roadway. As of 2021, maritime transport carries more than 80 percent of global trade by volume. It plays a critical role in the supply of essential goods such as food, clothing, shelter, and pharmaceuticals to countries. Fish fuel a $362 billion global industry. Millions of people in coastal communities depend on the fishing industry for their livelihood. Some 4.6 million fishing vessels of all sizes now ply the ocean, many with increasing capacity and efficiencies to catch more fish.

We drill for oil. Offshore oil drilling accounted for about 16 percent of the 12.2 million barrels of oil produced each day in the U.S. in 2019, according to federal records. But oil drilling pollutes our waters, land, and air. And drilling increases the risk of oil contamination to wildlife as well as destroys habitats.

Biomedical Research

We also mine our ocean for medicines. Most drugs in use today come from nature—many from flowers and plants on land. Aspirin, for example, was first isolated from the willow tree. As demand grows for new medicines, specifically anti-cancer and anti-inflammatory substances, researchers are looking to the ocean. Two such drugs are already in use—an anti-tumor medication made from sea squirts and a painkiller from a cone snail. More than a dozen other drugs are being tested, including ones to treat Alzheimer’s disease and lung cancer.

One group of researchers is focusing on the layer of mucus that coats some species of fish. This coating protects fish from bacteria, fungi, and viruses. Could this fish slime protect people, too? Could it be copied in a lab and produced in large quantities? If so, we could avoid harvesting it from the ocean, leaving our marine ecosystems healthy and intact.

Tourism and Recreation

Travel and tourism form one of the world’s largest industries, supporting more than 100 million jobs. Many visitors come to the ocean for nature-based tourism, such as diving, snorkeling, or whale-watching. Others come to enjoy the less direct benefits of swimming in calm waters or lying on white sandy beaches. More than 350 million people annually travel to coral reefs. Some go to see specific animals. An estimated 600,000 people spend more than $300 million (in U.S. dollars) annually to watch sharks, for example. In Palau, a population of about 100 sharks support $18 million worth of shark diving each year.

A New Frontier

More than 80 percent of our ocean is unmapped and unexplored. Let that sink in for a minute. Despite its size and impact on the lives of every organism on Earth, we know more about the surfaces of the moon and the planet Mars than we know about our own ocean floor. How can that be? Well, as marvelous a place as the ocean is, it’s also really challenging to explore and study.

Sunlight penetrates only the top 200 meters (645 feet) of the ocean. So, the deeper we go, the darker and colder it becomes. There’s also more pressure. At any depth in the ocean, the weight of the water above pushes on an object below it.

On land, our bodies experience an internal pressure of one atmosphere (atm). Pressure in the ocean increases about one atmosphere for every 10 meters (32 feet) of water depth. So, for example, at a depth of 100 meters, the pressure is 10 times greater than the pressure at sea level.

If we wanted to join a sperm whale on its hunt for giant squid, we’d need to swim down to about 2,000 meters (7,000 feet). At that depth, the pressure would be 200 atmospheres. That’s too much pressure for people; we’d be crushed!

To explore and study the full water column and the seafloor, we need specialized technologies such as SCUBA (Self Contained Underwater Breathing Apparatus), submersibles, and remotely operated vehicles.

With every breath we take, every drop we drink, we’re connected to the ocean. But our ocean faces major threats: overfishing, warming and acidification, Pollution, habitat destruction, and invasive species. Nearly 66 percent of the ocean is under cumulative stress, at an accelerating pace, from human activities. Easing these pressures is crucial to human survival.

Overfishing

Overfishing happens when we take fish out of the ocean faster than they can reproduce. Fish are a “renewable” resource in that they reproduce and can replenish their own populations but not if we catch too many of them too fast.

Overfishing became a global problem in the last century, as large-scale, industrial fishing methods grew to meet the demand of a rapidly growing human population. This demand has contributed to the development of more intensive fishing methods.

When you think of “fishing,” you probably don’t think of dynamite. But “blast fishing” or “fish bombing” is a destructive fishing practice that uses explosives to stun or kill schools of fish for easy collection. This often illegal practice destroys the underlying habitat that supports fish.

Trawling is one of the most harmful fishing methods. Enormous nets as wide as a football field are dragged through the water or across the seafloor, capturing almost everything in their path. Vulnerable habitats are damaged in the process. Every year, trawlers around the world drag nets that impact an area equivalent to twice the size of the U.S. while producing carbon dioxide emissions similar to those of global aviation.

Gill nets are walls of netting that drift in the water. Gill nets can be up to 3.2 kilometers (two miles) long. They are designed to trap fish around the gills when they try to swim through.

Longline fishers use lines that can extend for up to 80 kilometers (50 miles), with thousands of baited hooks branching off from the main line. These baited hooks often attract an array of other species, including diving birds.

These destructive practices have severe consequences for marine life: The global fishing catch has been declining since 1996. And today—according to the UN—90 percent of our fish stocks are said to be overfished or fished to full capacity, meaning they are close to reaching the level at which they will collapse.

Removing too many fish too fast can have a cascade-like effect across the marine ecosystem. It can reduce the size of fish remaining, as well as how much they reproduce and the speed at which they mature. Marine food webs are highly complex. Removing an apex predator, like sharks, or the base of the food web, like krill, could cause an entire ecosystem to collapse.

Overfishing is closely tied to bycatch—the capture of unwanted sea life while fishing for a different species. This, too, is a serious marine threat that causes the needless loss of billions of organisms, including hundreds of thousands of sea turtles and cetaceans.

Overfishing is only made worse by illegal catches and trade. Experts estimate illegal, unreported, and unregulated (IUU) fishing brings in up to $36.4 billion each year.

Food and Economic Security

Demand for fish continues to increase around the world, and that means more businesses and jobs are dependent on dwindling stocks. Aquaculture is the practice of breeding and farming fish for food rather than taking them from wild populations. In 2018, about 60 million people were employed by the fisheries and aquaculture sector.

Marine Pollution

Our ocean is filled with items that do not belong there. Marine pollution is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. Huge amounts of plastic, metal, rubber, paper, textiles, and other lost or discarded items enter the ocean every day. Debris can range in size from small plastic pieces, called microplastics, to huge abandoned vessels and gear. Although some of these items may eventually break down, others are made to last a long time—sometimes hundreds of years. Most marine debris is preventable.

Impact of Marine Debris

The National Oceanic and Atmospheric Administration (NOAA) tells us that marine debris can cause harm in the following ways:

Ingestion: Animals mistakenly eat plastic and other debris. More than 40 percent of seabird species eat plastic. All sea turtle species eat debris.

Entanglement: Marine life gets caught and killed in abandoned gear, nets, plastic bags, or other debris. Worldwide, more than 350 species are impacted by entanglement.

Habitat damage: Heavy marine debris crushes sensitive habitats, such as coral reefs and seagrass.

The problem isn’t just trash, though. Nutrient pollution from the overuse of fertilizers on farms runs into waterways that ultimately flow into the ocean. This increased concentration of chemicals, such as nitrogen and phosphorus, can be toxic to wildlife and harmful to people.

Ocean Warming

We know that our ocean is getting warmer as a result of the burning of fossil fuels and other activities. Since 1971, the ocean has absorbed 90 percent of the excess heat generated by our actions. Water can hold more heat than land or air, but this rate is alarming. The ocean’s surface layer, home to most marine life, takes most of this heat. As a result, fish species migrate farther to find cooler temperatures and food sources. This impacts communities and economies that depend on fishing. A warmer ocean can also change ocean chemistry, raise sea levels, and fuel extreme weather.

Ocean Acidification

As the amount of CO2 in the air increases from industry and other activities, the excess CO2 enters the ocean. This changes the chemistry of seawater.

When CO2 enters the ocean, it dissolves and reacts with water, making it more acidic. What can happen as a result?

• It can reduce fish size and populations. Some fish grow slower, others may have difficulty reproducing.
• Some types of marine life have more difficulty avoiding predators.
• Animals that rely on shells become vulnerable. One reason for this is less carbonate in the ocean water. Carbonate is a necessary building block in skeletons and shells. Animals like corals and mollusks are at risk.
• Phytoplankton and zooplankton, which are the base of the marine food chain, are destroyed.

Rising Sea Levels

Warmer ocean waters also contribute to rising sea levels. Since 1880, average sea levels have swelled about 23 centimeters (more than eight inches), including about 7.6 centimeters (three inches) in the last 25 years. Every year, the sea rises about 3.6 millimeters (0.14 inch). New research projects this rise to accelerate.

The change is driven by three factors. First, when water heats up, it expands. About half of the sea-level rise over the past quarter century is a result of the water just taking up more space. Second, persistent higher temperatures are causing our glaciers to melt. And third, increased heat is causing the massive ice sheets that cover Greenland and Antarctica to melt more quickly. Higher waters can mean big trouble. Even small increases can have devastating effects on coastal habitats—causing destructive erosion, wetland flooding, aquifer and agricultural soil contamination, and lost habitat for fish, birds, and plants.

Extreme Weather

Rising ocean temperatures are also connected to weather extremes. Warmer sea surface temperatures influence weather patterns and shift precipitation. Some regions may experience intense rainstorms and flooding. Others may undergo drought conditions or wildfires. These changes spawn dangerous hurricanes and typhoons that move more slowly and drop more rain, which can strip away everything in their path.

If we are to create a planet in balance, our current practices must change.

Marine Protected Areas

We know that our ocean and its rich diversity are threatened by human impacts at all levels, there are proven solutions. Marine protected areas, or MPAs, are a key strategy for sustaining and restoring ocean ecosystems. MPAs are like national parks in the sea. MPAs that ban overfishing or other damaging activities constitute the most effective solution to restore ocean life and all the benefits it provides to people. Marine protected areas directly address three of the major problems affecting humanity: 1) the biodiversity crisis, 2) food security for a growing population, and 3) climate change.

How MPAs Protect

If well designed, MPAs can safeguard essential habitats, such as nurseries and feeding and breeding grounds. They shield vulnerable ecosystems and endangered species. They help maintain functional food webs.

MPAs are an effective tool for restoring ocean biodiversity and ecosystems and building resilience for future warming events and other natural disasters. Protected areas are able to rebound at a faster rate than they would if they weren’t protected.

Marine reserves help boost the yield of fisheries, increasing fish and food security for those who depend on the ocean for sustenance. They help secure marine carbon stocks. MPAs also support coastal communities and economies. They create opportunities for recreation and tourism, research, and education. Areas of cultural and historic significance, such as those of importance to Indigenous peoples, archeological sites, and shipwrecks, are often included in MPAs. And they help local fishing by replenishing adjacent fishing grounds through spillover of larvae and adult fish.

Ocean Problems

• Overfishing and global warming are depleting ocean life and bringing the ocean to a tipping point
• Coral reefs and other critical habitats are being annihilated by ocean warming and acidification
• 90 percent of the large fish in the ocean are gone
• 82 percent of fish stocks that are overexploited
• Loss of ocean biodiversity threatens the well-being of humanity and poses huge economic risks

MPA Solutions

• Average increase of 600 percent in fish biomass in fully protected MPAs
• MPAs help capture carbon and provide climate resilience
• Global science-based target to protect 30 percent of ocean surface by 2030
• Marine protected areas (MPAs) restore ocean biodiversity and its benefits to people
• MPAs help replenish fish stocks and improve food security

The international union for conservation of nature (iucn) tells us that mpas are “clearly defined geographical spaces, recognized, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values.”

Levels of Protection

Not all MPAs are created equal.

Fully Protected MPAs › No mining, prospecting, or exploitation. No active pipelines allowed with potential to leak. No dredging or dumping of any kind. Only small-scale, short-duration anchoring with low impact. Only minimal-impact, small-scale infrastructure for conservation, scientific, navigational, or sustainable tourism purposes. Aquaculture is allowed only for restoration, not extraction. No fishing of any kind. Non-extractive activities include only small-scale, closely regulated use with low impact (snorkeling, swimming, scuba diving, tide pooling), cultural/ ceremonial gatherings, cultural education, teachings/ knowledge transmission, and other uses.

Highly Protected MPAs › No mining, prospecting, or exploitation. No active pipelines allowed with potential to leak. No dredging or dumping of any kind. Only small-scale, short-duration anchoring with low impact. Low-impact, small-scale infrastructure allowed (facilities associated with sustainable tourism and aquaculture, renewable-energy structures, artificial reefs). Aquaculture is allowed but only unfed aquaculture that is small-scale and low density. Infrequent fishing with only a few (five or fewer) gear types that are highly selective and low impact. For non-extractive activities, only small-scale, closely regulated use with low impact (snorkeling, swimming, scuba diving, tide pooling), cultural/ ceremonial gatherings, cultural education, teachings/ knowledge transmission, and other uses.

Lightly Protected MPAs › No mining, prospecting, or exploitation. No active pipelines allowed with potential to leak. Limited dredging allowed for navigation, restoration, shoreline protection, and for coastal erosion and safety. Moderate unregulated anchoring, anchoring in sensitive habitats allowed only if anchored at the same location for a short time. Some infrastructure allowed—moderate-impact facilities associated with sustainable tourism and aquaculture, renewable-energy structures, artificial reefs (may allow fishing). Unfed aquaculture that is commercial scale and semi-intensive to intensive; or fed aquaculture that is small-scale and low density allowed. Also, low-density, small-scale/traditional use (fish, shrimp). Fishing is allowed but with moderate number (10 or fewer) gear types. Unregulated use or high-impact, high-density, and/or large-scale non-extractive activities allowed.

Minimally Protected MPAs › No mining, prospecting, or exploitation. No active pipelines allowed with potential to leak. Limited dredging allowed for navigation, restoration, shoreline protection, and for coastal erosion and safety. Large-impact anchoring allowed only if compatible with biodiversity conservation goals. Large-impact infrastructure allowed only if compatible with biodiversity conservation goals. Fed aquaculture that is commercial scale and semi-intensive is allowed; may be located in or close to sensitive habitats. Fishing is allowed with high number (more than 10) gear types that are large impact but not industrial. Unregulated use or high-impact, high-density, and/or large-scale nonextractive activities allowed.

The higher the level of protection, the stronger the conservation outcomes.

Scope and Scale

There are currently more than 16,000 MPAs around the world. That might sound like a lot, but they cover only about 8 percent of our ocean. And less than 3 percent of the ocean is in highly or fully protected MPAs.

Approximate size of the world’s ocean: 363 Million km2 

Total size of the world’s marine protected areas: 29 Million km2 (That’s a little more than the combined size of Russia and Canada.)

Total size of the world’s highly and fully protected MPAs: 8.8 Million km2 (That’s a little smaller than the size of the United States.)

MPAs lead to:

• Bigger fish
• Greater diversity of species
• Protection of carbon stocks
• Respect for cultural traditions and practices
• Opportunities to study and learn
• Healthier fisheries for jobs and food security
• Tourism that supports economies

Based on scientific guidance, more than 100 countries have agreed to a goal of protecting at least 30 percent of the ocean by 2030.

Marine protected areas mean:

1 › Marine life recovers fish abundance increases on average 600 percent in marine reserves after full protection within a decade.

2 › Better fishing fish spill over the reserve boundaries and help to replenish adjacent fishing grounds. In california, local fishers are catching 225 percent more lobsters after protecting 35 percent of their fishing grounds—only six years after the reserve was created.

3 › Diving tourism when the fish come back, divers come in. In the medes islands, diving tourism employs hundreds of people and brings in 12 million euros per year—24 times more than fishing.

4 › Mitigate global warming the protection of carbon-rich sediments has the potential to avoid carbon dioxide emissions similar to those of global aviation, helping to mitigate global warming.

5 › Global benefits protection also produces benefits like oxygen production. This phenomenon has a global impact, since all life is connected to the ocean.

National Geographic Pristine Seas

Feeling that as an academic scientist he was just writing the obituary of the ocean, marine biologist Enric Sala quit academia in 2008 to dedicate his life to ocean conservation as a National Geographic Explorer in Residence. Sala was a professor at the Scripps Institution of Oceanography in California when he decided to take a more active role in protecting our ocean and restoring richness and diversity to counteract the decline he was documenting.

Pristine Seas is the National Geographic Society’s flagship ocean conservation initiative. It protects vital places in the ocean by combining exploration, research, media, economics, communication, and policy, in collaboration with local communities, Indigenous peoples, and governments.

How the Work Gets Done

It takes months to plan and prepare for a Pristine Seas expedition. Experts and local partners from varying disciplines team up to document and assess a target area’s biodiversity. Data gathered during the expedition are shared with the scientific community, government authorities, local communities, and Pristine Seas partners to inform the need for and design of a marine protected area. Traditional conservation practices of local and Indigenous communities—some of which have been in place for centuries—provide important models for the Pristine Seas team.

To date, Pristine Seas has carried out 36 expeditions in more than 20 countries and has worked with local communities to inspire the creation of 25 of the largest marine reserves in the world. These MPAs cover more than 6.5 million square kilometers of ocean—an area two-thirds the size of the United States—where marine life thrives and helps replenish surrounding areas.

Pristine Seas will work with local communities, governments, and partners to establish new marine protected areas and catalyze the global community to protect at least 30 percent of the ocean by 2030.

MPAs at Work: Recovering Cabo Pulmo

When Juan Castro Montaño was a boy in Cabo Pulmo, Mexico, fish were plentiful. “Fishing was very important for this community because that was our means of living,” he said. Over time, commercial fishing took hold and grew to unsustainable levels. When the local community saw that their fish population was declining, they did something extraordinary. In 1995, they asked the Mexican government to create a national park in the sea to give their reef a chance to recover. This was not an easy choice. It meant that the people who made their living as fishers had to find a new path for themselves and their families.

“We stopped fishing from one day to the next,” said fisher Mario Castro Lucero. “Now we work in ecotourism. It was very, very difficult, but we made it. It is a way of preserving the reef and dedicating ourselves to something else.”

The results were astonishing. Cabo Pulmo National Marine Park has experienced the greatest recovery ever observed in a marine protected area. During a 10-year period, fish biomass increased by more than 460 percent, bringing the reef to a level of biomass (the accumulation of living matter) similar to that of a reef that had never been fished. “I think that my dad, my grandfather, seeing how the reef has recovered, would think of how it was when they were young. And they would say: ‘It came back. The riches that we had as kids came back.’ I think they would have been very proud,” said Mario.

Juan agreed. “Other generations will see this when we’re gone. We’re the sentinels, watching over and taking care of it.”

Cabo Pulmo became a model for Pristine Seas.

The Role of Pristine Seas

During 200 hours of scientific surveys at 39 locations, the Pristine Seas team assessed the biodiversity of the outer islands of the Seychelles. They found the island waters teeming with life. Working with local officials and nonprofit organizations, the team collected data that informed a proposal to create large no-take areas around the outer islands. Informed by their findings, the government of Seychelles created a 74,400 square-kilometer highly protected MPA around the outer islands, covering 10 percent of their waters.

Voices of Conservation: Alvania Lawen, Seychelles

For Alvania Lawen, a young ocean advocate living in the Seychelles, protecting these islands is a personal mission:

“Life in Seychelles is deeply integrated with the ocean. Protecting the ocean feels normal to me, like I’m meant to do it. I got my start in marine conservation at age 11 when I began snorkeling and experienced firsthand our diverse underwater life. From there I joined a successful campaign to ban certain single-use plastics led by the nongovernmental organizations (NGOs) Sustainability for Seychelles and SYAH-Seychelles. I advocated for plastic alternatives. Our combined efforts led to bans on the importation and distribution of items such as plastic bags and cups in 2017.

In Seychelles, our economy depends on tourism, and the tourism sector depends largely on the marine environment. The term ‘blue economy’ refers to this sustainable economic use of the ocean. NGOs play a big role in environmental protection here, and I am part of several women- and youth-led NGOs with an environmental focus.

Young people like me can make a difference. We can use social media as a tool to protect the ocean. You don’t need to be Instagram-famous or have a ton of followers, as long as you stay focused on your goals and make connections with like-minded people and organizations. Try to treat any negative news, such as an alarming report about climate change, as a reason to persist in your work.”

MPAs at Work: Discovering Nature's Resilience

In the remote Pacific Ocean, a chain of coral islands and atolls straddling the Equator make up the ecologically diverse southern Line Islands. Part of the Republic of Kiribati, these specks of land are among the most isolated atolls on Earth. They are uninhabited and rarely visited.

Divers spent more than a thousand hours underwater around the five islands in 2009. What they found astonished them. On some reefs, the corals were so dense they covered 90 percent of the seabed—vastly more than the average coral cover found in the Caribbean, which is typically less than 10 percent.

In parts of the lagoon at Caroline Island (Millennium Atoll), the density of giant clams reach up to four per square foot—an almost-unheard-of abundance for creatures highly sought for their meat and shells. These giant filter feeders act as water purifiers, cleansing the water of bacteria that can cause diseases in corals, fish, shellfish, and crustaceans.

As a result of the Pristine Seas team’s findings, the government of Kiribati announced that a 12-nautical-mile area around the southern Line Islands would be closed to commercial fishing beginning in 2015. This area was to be protected so that it could remain pristine. But then disaster struck.

Across the Pacific, water-temperature spikes caused by El Niño weather events in 2016 killed off massive amounts of corals. The Pristine Seas team returned to the islands in 2021, expecting to see destruction. But the reefs of the southern Line Islands had bounced back spectacularly. How? Corals tend to be resilient in places where other elements of the marine ecosystem are flourishing, too. In the southern Line Islands, the large abundance of fish kept the dead coral skeletons free of seaweed and provided the conditions for corals to grow back. As a result of its protected status, this place was resilient in the face of disaster.

MPAs at Work: Supporting Indigenous Solutions

Kawésqar National Park is one of the largest parks in the world and the second largest terrestrial park in Chile. The kelp forests off the coast of southern Chile are some of the healthiest on Earth.

In early 2020, Pristine Seas went on an expedition to the Patagonian fjords in partnership with the local Kawésqar and Yagan Indigenous communities. The explored area is threatened by intensive salmon aquaculture, which has become a major industry in Chile. Unfortunately, this industry has severe environmental, sanitary, and social impacts. The team conducted comprehensive scientific surveys of coastal and deepwater ecosystems and learned from members of the Kawésqar and Yagan about the cultural and ecological significance of the region. Pristine Seas is now supporting these communities to keep their culture alive and obtain full protection of their territories as a source of their identity, worldview, subsistence, and ancestral rights. The team produced a full scientific and cultural report from the expedition and a documentary film about this journey.

Protecting our ocean and restoring it to full health is a big task. There is no one-size-fits-all solution, but there are many things that we can do—individually and collectively—to help.

• Remember that our land and sea are connected. Visit your local MPA, or local coast, river, or lake to explore, snorkel, dive, or connect with nature.
• Boycott unsustainable fishing. Don’t eat unsustainable seafood. Look for labels that say “diver-caught” or “line-caught."
• Reduce your carbon footprint. Use less fossil fuel energy in daily life. Drive your car less or take public transporation. Reduce energy use by choosing energy-efficient appliances, and learn about solar initiatives in your community.
• Reduce the amount of waste you produce.
• Reuse items when you can. Choose reusable items over disposable ones. Recycle as much as possible. Avoid plastic bags. Buy second hand clothing instead of new.
• Conserve water. Freshwater is a limited resource, and it’s scarce in many parts of the world. Using less water leads to less runoff and wastewater dumped into the ocean.
• Volunteer. Conservation groups need your help.
• Lead or participate in a community cleanup. By picking up the trash we find on our local streets, rivers, streams, or beaches, we can prevent that waste from becoming marine debris.
• Plant trees. Our trees and forests help reduce atmospheric carbon dioxide, taking pressure off our ocean.
• Eat a plant-rich diet. Buy local produce to reduce transportation and production emissions.
• Watch what you flush! Avoid flushing household cleaners, pesticides, drain cleaner, and cat litter, because those chemicals can seep into our ocean, rivers, and lakes.
• Follow Explorer Enric Sala and Pristine Seas social media and stay up-to-date on their efforts across the globe. twitter.com/Enric_Sala instagram.com/enricsala/
• Learn, then teach. When we understand how our ecosystems work, we can take steps to protect them. Learn as much as you can, then raise awareness by sharing what you know with others.
• Speak up. Advocate for the change you want to see in your community and in the world.

Call to Action

What can you do in your community? After reading this handbook and seeing some of the suggestions on page 31, create a personal action plan to help conserve the ocean. Ask yourself a few key questions:

1 › What do you think is the best way to promote ocean conservation in your community?

2 › What are the advantages of this action or solution?

3 › Can you think of any disadvantages?

4 › What more do you need to know or to research to make a full plan?

5 › Make a list of all the parts of your plan. What will you do first? What next?

6 › Is this a plan that you can accomplish on your own or will you need help?

7 › List some individuals or groups who might be willing to support your idea.

8 › How might you approach these people to get their help?

9 › Create a timeline for your plan. How long will it take to do each part?

10 › Share your plan with others and get feedback.

11 › Refine the plan according to the feedback.

12 › When the plan is ready, take action!

Need to Know More?

If you’d like to know more about our ocean, the threats against it, and how you can help, consider using some of these resources:

• Pristine Seas
• Online Courses For Educators
• One Ocean Educator Guide (for Professional Learning)
• Earth Day 2021 Guide focused on the ocean
• Geo-Inquiry

For Learners

Citizen Science

• iNaturalist and Seek
• Sea-to-Source Toolkit
• MapMaker Pristine Seas

Offline Resources

This section includes example resources that could be downloaded or transmitted to communities that may not have access to strong internet. Many of these resources can be printed or downloaded to PDFs or zip files. Look for the appropriate icons on each resource next to the social media icons, typically just below the resource photo.

• Sustainable Fishing : A leveled encyclopedic entry that introduces the topic and defines key terms. Can print or save to PDF.

Spanish edition:

Recuperar el Océano

Introducción a la Conservación del Océano

Introducción

Crecí a orillas del mediterráneo. De niño me fascinaba la vida que se dejaba ver en las aguas someras de la playa: algas, anémonas, cangrejos pequeños y pececillos. No vi ningún animal marino grande hasta que me saqué el título de buceo y me sumergí en una reserva marina de protección integral. Recuerdo esa primera inmersión como si fuera ayer. Todos los peces que no podía ver en mi niñez estaban allí: los meros, las doradas, las lubinas.

Tuve que estudiar muchos años hasta entender plenamente cómo funcionaba el océano, los daños que le causamos y qué hace falta hacer para recuperarlo. Espero que este manual sea la introducción que hubiera necesitado aquel niño que anhelaba formar parte del mar.

Enric Sala Explorador en Residencia de National Geographic

Tres rostros tengo. Uno mojado para colmar tu sed. Uno tan liviano que sube al cielo. Y otro tan duro que cortaría una piedra. ¿Quién soy?

El agua es la única sustancia de la Tierra que aparece en la naturaleza en estado sólido, líquido y gaseoso. Es lo que define nuestro planeta. La mayor parte está en los océanos. En los polos se encuentra en estado sólido y en el aire en forma de gas.

La Tierra es un sistema cerrado. Su agua es finita. O sea, el agua que hay dentro, sobre y por encima de la Tierra ni aumenta ni disminuye, sino que fluye eternamente por el océano, la atmósfera y la tierra en el llamado ciclo del agua .

Casi toda la tierra está cubierta de agua: 29 por ciento tierra, 71 por ciento agua

Casi toda el agua es salada: 3 por ciento agua dulce, 97 por ciento agua salada

La gente tiene acceso a una porción muy limitada de agua: 0.3 por ciento accessible, 99.7 por ciento almacenada en el océano, el suelo, los polos y la atmósfera

Nuestro Océano

Sobre el Mapa

Aunque hay un solo océano global, la enorme masa de agua que recubre nuestro planeta está geográficamente fragmentada en regiones diversas con nombres específicos. Las fronteras de estas regiones han ido cambiando con el paso del tiempo por razones culturales, geográficas y científicas. Seguramente conocerás estas regiones marinas como océano Atlántico, Pacífico, Índico y Ártico. Hace no mucho tiempo, el océano Austral, en torno a la Antártida, se incorporó a la lista. Todas estas cuencas oceánicas están conectadas y forman un solo océano global.

Cada cuenca oceánica está formada por el lecho marino y sus accidentes geológicos: cañones, islas, cordilleras, volcanes y montañas submarinas. Los movimientos de la corteza terrestre hacen que las cuencas cambien de tamaño y forma. Algunos de los picos más altos, valles más profundos y vastas planicies de la Tierra están bajo el mar.

Océano en Movimiento

El océano nunca para. Sus aguas circulan impulsadas por corrientes rápidas de superficie y otras más lentas de profundidad. Las de superfice están impulsadas por el viento y la rotación de la Tierra. Las más profundas están causadas por la temperatura y la salinidad . Esto se debe a que tanto el calor como la sal afectan a la densidad del agua marina. El agua salada es más densa que el agua dulce. El agua fría es más densa que el agua cálida. El agua más densa se hunde.

El movimiento de los océanos siempre busca un estado de equilibrio. Por ejemplo, cuando el agua superficial se enfría, se hace más densa y se hunde. El agua más cálida del fondo sube a la superficie para ocupar el espacio que dejó el agua superficial al hundirse.

Las corrientes oceánicas recuerdan mucho a las cintas transportadoras que llevan las maletas en los aeropuertos, aunque el océano no se mueve tan rápido como las maletas. Los científicos estiman que la cinta transportadora oceánica tarda unos mil años en dar la vuelta al mundo.

La cinta transportadora mantiene nuestro planeta templado. Cuando la luz del sol llega a la superficie de la Tierra, el océano absorbe parte de esa energía y la almacena en forma de calor. Las corrientes oceánicas distribuyen el calor por todo el mundo. Las aguas superficiales más cálidas del ecuador se desplazan hacia los polos, y las aguas frías y profundas de los polos viajan hacia los trópicos. Sin este intercambio global, las regiones ecuatoriales serían mucho más calurosas, las regiones polares serían mucho más frías y las zonas habitables de la Tierra serían muy reducidas.

Como ya sabemos, la creciente concentración de gases de efecto invernadero está atrapando más energía del sol en nuestra atmósfera. El agua almacena más calor que el aire y, por tanto, un leve aumento de la temperatura del aire hace que el océano absorba más energía térmica. De hecho, nuestro océano ha absorbido más del 90 por ciento del calor adicional generado en la Tierra desde 1955.

La temperatura del océano es clave en el sistema climático, ya que las tempestades se alimentan del calor de las aguas superficiales del océano. El creciente calentamiento del planeta hace que cada vez experimentemos vientos más fuertes, marejadas ciclónicas más intensas y precipitaciones sin precedentes, todo lo cual hace que las tempestades sean más y más destructivas y costosas.

Seguramente habrás oído hablar del clima y del tiempo. El clima hace referencia al tiempo atmosférico durante todo el año en una región específica. El tiempo alude a las condiciones atmosféricas de un lugar específico. Esta sería una forma de entenderlo: ¿qué hay en tu armario? El tiempo te dicta lo que tienes que llevar puesto hoy. El clima determina el tipo de prendas que tienes en todo el armario.

Los Pulmones de la Tierra

Quizá hayas oído decir que las selvas tropicales de la Tierra son como un pulmón, porque toman dióxido de carbono y expulsan oxígeno. Pero al igual que la mayoría de nosotros, la Tierra tiene dos pulmones. El océano es su segundo pulmón.

El océano depende de unos pequeños organismos unicelulares conocidos colectivamente como fitoplancton . La célula de fitoplancton mide menos de la mitad del grosor de un pelo humano; en el océano hay mil millones de billones de estos organismos, que son críticos para la vida en la Tierra. El fitoplancton genera aproximadamente la mitad del oxígeno del planeta: anualmente representa tanto como todas las plantas terrestres juntas.

A través de la fotosíntesis, el fitoplancton consume dióxido de carbono y libera oxígeno. Cuando el fitoplancton muere, se hunde y arrastra al fondo marino parte de ese carbono. Este proceso, llamado secuestro de carbono , elimina de la atmósfera gases de efecto invernadero. El océano almacena 50 veces más dióxido de carbono que la atmósfera, y la capa más externa de sedimentos del fondo marino almacena el doble de carbono que la tierra.

Parte del carbono es transferido por el fitoplancton a diversas capas de profundidad, donde es consumido por otros animales. El fitoplancton es la base de prácticamente todas las redes alimentarias acuáticas. Es consumido por todo tipo de criaturas, desde unos animalillos microscópicos conocidos como zooplancton a las descomunales ballenas.

Biodiversidad

Sabrás que el océano encierra la mayor biodiversidad del planeta. La biodiversidad marina se refiere a las diversas formas de vida que moran en nuestro océano: desde animales y plantas a microorganismos. Aunque pueda parecernos una idea sencilla, es un concepto complejo que puede medirse de diversas maneras.

Diversidad de Especies: (también conocida como Riqueza de Especies ) es el número de especies de un lugar determinado. El número de especies de pez de un lago, por ejemplo.

Diversidad Genética: gama de rasgos heredados propios de una especie. Una población con gran variedad de rasgos diferentes, es probable que tenga una gran diversidad genética.

Diversidad Funcional: complejidad ecológica de un ecosistema. La presencia de múltiples organismos con funciones diversas en una red alimentaria indica un nivel elevado de diversidad funcional.

Sabemos que cada especie forma parte integral de su respectivo ecosistema y cumple funciones esenciales en dicho ecosistema. Por ejemplo: los corales forman esqueletos de caliza que a lo largo de los siglos acaban creando arrecifes de coral y actúan a modo de barreras protectoras de islas y atolones coralinos, conformando el hábitat de muchas especies.

Las especies también cumplen estas funciones en sus respectivos ecosistemas:

• Producir oxígeno
• Producir materiales orgánicos
• Descomponer materiales orgánicos
• Filtrar el agua y reciclar nutrientes
• Controlar la erosión y las plagas
• Regular el clima y los gases atmosféricos

Al eliminar especies de los ecosistemas, eliminamos también estas importantes funciones. Cuanta mayor sea la diversidad de un ecosistema, mayor será su capacidad para mantener su equilibrio y productividad, y para resistir los factores ambientales de estrés. La biodiversidad hace que nuestro océano sea productivo y resiliente, y adaptable a los cambios ambientales. Decimos que un sistema ecológico es resiliente cuando puede recuperarse tras sufrir un episodio destructivo: por ejemplo, cuando un arrecife de coral revive tras un periodo de calentamiento.

La biodiversidad tiene un valor intrínseco porque cada especie:

• Genera un valor que trasciende su contribución económica, científica y ecológica
• Forma parte de nuestra herencia cultural y espiritual
• Es bella y singular
• Tiene derecho a vivir en este planeta

La biodiversidad es clave:

• Como recurso alimentario
• En la industria
• En la investigación biomédica
• En el turismo y el ocio

Recursos Alimentarios

El pescado es un elemento clave y nutritivo en la dieta de muchas áreas del mundo, especialmente entre las comunidades costeras. El pescado suministra casi el 20 por ciento de proteínas de origen animal a unos 3,300 millones de personas. El consumo mundial de pescado aumentó un 122 por ciento entre 1990 y 2018, y se espera que esta cifra siga aumentando.

Usamos el océano como medio de transporte. En 2021, el transporte marítimo representaba más del 80 por ciento del volumen del comercio mundial. Desempeña un papel fundamental en el suministro de bienes esenciales como alimentos, ropa, vivienda y productos farmacéuticos. La pesca representa una industria global por valor de $362,000 millones. Son innumerables las comunidades costeras que dependen de la pesca para su sustento. Unos 4.6 millones de buques pesqueros de todos los tamaños peinan el océano con una creciente capacidad y eficiencia.

Petróleo en el mar. En 2019, las perforaciones petroleras en alta mar representaron cerca del 16 por ciento de los 12.2 millones de barriles de petróleo producidos cada día en EE. UU., según fuentes federales de EE. UU. Las perforaciones petrolíferas contaminan el mar, la tierra y el aire, amenazan la flora y la fauna, y destruyen los hábitats.

Investigación Biomédica

También escrutamos el océano en busca de medicinas. La mayoría de los fármacos actuales proceden de flores y plantas terrestres, y de otros recursos de la Naturaleza. La aspirina, por ejemplo, se aisló por primera vez del sauce. Ante la creciente demanda de nuevos medicamentos (específicamente de anticancerígenos y antiinflamatorios) la ciencia está empezando a buscarlos en el océano. Ya se han aprobado dos de estos medicamentos: un fármaco antitumoral y otro para el dolor extraídos de la jeringa de mar y del caracol cono, respectivamente. Se están probando más de una docena de otros medicamentos, incluidos algunos para tratar el alzhéimer y el cáncer de pulmón.

Un grupo de científicos está investigando una mucosa que recubre la piel de algunas especies de pez. Este recubrimiento los protege de bacterias, hongos y virus. ¿Podría esta mucosa de pescado proteger también a las personas? ¿Podría ser replicada en un laboratorio para ser producida en grandes cantidades? Si se pudiera, evitaríamos tener que sacarla del océano para no afectar a los ecosistemas marinos.

Turismo y Ocio

El ocio y el turismo generan más de 100 millones de empleos en todo el mundo. Muchas personas van al océano en busca de experiencias naturales, ya sea buceo, esnórquel o avistamiento de ballenas; otros, simplemente van a nadar en aguas abiertas o a tomar el sol en playas de arena blanca. Cada año más de 350 millones de personas acuden a los arrecifes de coral. Algunos van a ver animales específicos. Se estima, por ejemplo, que cada año 600,000 personas gastan más de $300 millones en observar tiburones. En Palaos, un centenar de tiburones genera cada año $18 millones en ingresos por actividades de buceo.

Una Nueva Frontera

Más del 80 por ciento de nuestro océano no está ni cartografiado ni explorado. Piénsalo. A pesar de su tamaño y de su importancia en la vida de todos los seres vivos, sabemos más sobre las superficies de la luna y del planeta Marte que de la de nuestro propio fondo marino. ¿Cómo es esto posible? El océano es fascinante, pero explorarlo y estudiarlo es realmente difícil.

La luz del sol penetra tan solo hasta 200 metros (645 pies): a más profundidad, menos luz y más frío ... y presión. El peso del agua que hay por encima de un objeto sumergido a cualquier profundidad ejerce una fuerza sobre él.

En tierra firme, nuestros cuerpos tienen una presión interna de una atmósfera (atm). La presión en el océano aumenta alrededor de una atmósfera por cada 10 metros (32 pies) de profundidad adicional. Es decir, a una profundidad de, por ejemplo, 100 metros, la presión es diez veces mayor que la que experimentamos a nivel del mar.

Si quisiéramos acompañar a un cachalote en su búsqueda de calamares gigantes, tendríamos que sumergirnos hasta unos 2,000 metros (7,000 pies). A esa profundidad, la presión sería de 200 atmósferas. ¡Cualquier persona quedaría aplastada bajo esa presión!

Para explorar toda la columna de agua y el lecho marino, hacen falta aparatos de respiración subacuáticos autónomos (SCUBA, por sus siglas en inglés), sumergibles y vehículos a control remoto.

Cada hálito de aire y cada gota de agua nos conectan al océano. Pero el océano se enfrenta a grandes amenazas: la sobrepesca; el calentamiento y la acidificación; la contaminación; la destrucción de hábitats y la introducción de especies invasoras. Casi el 66 por ciento del océano está sometido al estrés constante y creciente de las actividades humanas. Aliviar estas presiones es crucial para nuestra supervivencia.

La sobrepesca se produce cuando capturamos los peces más rápido de lo que pueden reproducirse. Los peces son recursos “renovables”, o sea, reponen sus propias poblaciones, siempre que no capturemos demasiados o cada poco tiempo.

La sobrepesca fue un problema global en el siglo pasado, ya que los métodos de pesca industrial a gran escala se extendieron para satisfacer la demanda de una población humana en constante aumento. Esta demanda ha dado lugar a métodos de pesca más intensivos.

Generalmente no asociamos la pesca con la dinamita, pero la pesca con explosivos , o “bombardeo de peces”, es una práctica pesquera destructiva para aturdir o matar bancos de peces y facilitar así su captura. Estos métodos son tan ilegales como destructivos.

La pesca de arrastre es uno de los métodos de pesca más dañinos. Enormes redes del tamaño de un campo de fútbol son arrastradas por el agua o por el fondo marino, capturando todo lo que encuentran a su paso y destruyendo hábitats vulnerables. Cada año, barcos de arrastre de todo el mundo utilizan redes que afectan a un área equivalente a dos veces la extensión de EE. UU., y emiten unos niveles de dióxido de carbono similares a los de toda la aviación mundial.

El trasmallo es un arte de pesca que forma una barrera de redes de hasta 3.2 kilómetros (dos millas). Los peces quedan atrapados por las agallas cuando intentan atravesarlas.

En la pesca con palangre se usan sedales que pueden extenderse hasta 80 kilómetros (50 millas), con miles de anzuelos provistos de cebo que cuelgan del sedal principal. Estos anzuelos con cebo suelen atrapar accidentalmente aves buceadoras y otras especies.

Estas prácticas destructivas tienen graves consecuencias para la vida oceánica. Las capturas pesqueras mundiales llevan disminuyendo desde 1996, y hoy en día, según la ONU, el 90 por ciento de las poblaciones de peces están sobreexplotadas o se pescan a su máxima capacidad; es decir, están a punto de colapsar.

Atrapar demasiados peces con demasiada rapidez puede tener un efecto en cascada en todo el ecosistema marino. Puede reducir el tamaño de los peces supervivientes, así como su capacidad de reproducción y el tiempo que tardan en madurar. Las redes alimentarias marinas son muy complejas. La pérdida de un depredador principal, como el tiburón, o de la base de la red alimentaria, como el kril, podría provocar el colapso de todo el ecosistema.

La sobrepesca está muy ligada a las capturas accidentales de especies no comerciales. Es también una seria amenaza que provoca la pérdida innecesaria de miles de millones de organismos, incluidos cientos de miles de tortugas marinas y cetáceos.

La sobrepesca no hace sino empeorar con las capturas y el comercio ilegales. Se calcula que la pesca ilegal, no declarada y sin regular (IUU, en sus siglas en inglés) representa unos $36,400 millones anuales.

Seguridad Económica y Alimentaria

La demanda de pescado sigue aumentando en todo el mundo, lo que significa que cada vez más empresas y puestos de trabajo dependen de un recurso a la baja. La acuicultura consiste en la práctica de criar y cultivar peces para la alimentación en lugar de atraparlos en sus hábitats naturales. En 2018, el sector de la pesca y la acuicultura daba trabajo a 60 millones de personas.

Contaminación Marina

Nuestro océano está lleno de cosas que no deberían estar allí. La contaminación marina es causada por productos químicos y basura que se origina en tierra y es arrastrada por el agua o el viento hasta el océano. Cantidades ingentes de plástico, metal, caucho, papel, tejidos y otros residuos llegan al océano cada día. Varían de tamaño, desde trocitos de plástico (microplásticos) a enormes embarcaciones y aparejos abandonados. Aunque algunos de estos objetos se descomponen, otros están hechos para perdurar cientos de años. Casi todas estas basuras marinas son evitables.

Consecuencias de los Residuos Marinos

Según la Oficina Nacional de Administración Oceánica y Atmosférica (NOAA, en sus siglas en inglés), los desechos marinos pueden causar daños de las siguientes maneras:

Ingestión: más del 40 por ciento de especies de aves marinas y todas las especies de tortuga marina comen basura.

Enredo: los animales marinos quedan atrapados y mueren en artes de pesca abandonadas, redes, bolsas de plástico y otros desechos. En todo el mundo, ejemplares de más de 350 especies se enredan en artes de pesca.

Daños al hábitat: los residuos marinos pesados aplastan hábitats sensibles, como los arrecifes de coral y las praderas marinas.

El problema no es sólo la basura. La contaminación por el uso excesivo de fertilizantes en las explotaciones agrícolas llega a los ríos que los arrastran al océano. La concentración de nitrógeno y fósforo, y otras sustancias es tóxica para la Naturaleza y los seres humanos.

Calentamiento Oceánico

Sabemos que nuestro océano se está calentando por el uso de combustibles fósiles y de otras actividades. Desde 1971, el océano ha absorbido el 90 por ciento del exceso de calor generado por el ser humano. El agua retiene más calor que la tierra o el aire, pero el ritmo actual es alarmante. La capa superficial del océano, que alberga casi toda la vida marina, absorbe casi todo ese calor. Como resultado, los peces migran más lejos en busca de aguas más frías y ricas en alimento. Esto afecta a las comunidades y economías pesqueras. Un océano más cálido cambia su química interna, aumenta el nivel del mar y genera climatologías extremas.

Acidificación del Oceano

A medida que aumenta la cantidad de CO2 en el aire a causa de la industria y de otras actividades, ese CO2 adicional llega al océano y cambia la composición del agua marina.

Cuando el CO2 entra en contacto con el océano, se disuelve y reacciona con el agua, volviéndola más ácida. ¿Qué ocurre entonces?

› Se reduce el tamaño de los peces y de sus poblaciones. Algunos peces crecen más lentamente, otros tienen dificultades para reproducirse.

› Algunas especies marinas tienen más dificultades para evitar a sus depredadores.

› Los animales con concha se hacen más vulnerables por la reducción del carbonato en el agua oceánica. El carbonato es un componente necesario para la formación de conchas y exoesqueletos. Esto afecta a organismos como los corales y los moluscos.

› Se destruye el fitoplancton y el zooplancton, base de la cadena alimentaria marina.

Aumento del Nivel del Mar

El calentamiento de las aguas oceánicas también contribuye a la subida del nivel del mar. Desde 1880, el nivel medio del mar ha subido unos 23 centímetros (más de ocho pulgadas), incluidos unos 7.6 centímetros (tres pulgadas) en los últimos 25 años. Cada año, el mar sube unos 3.6 milímetros (0.14 pulgadas). Recientes estudios prevén que esta subida se intensificará.

Esto se debe a tres factores: en primer lugar, cuando el agua se calienta, se expande. El 50 por ciento de la subida del nivel del mar del último cuarto de siglo se debe al mayor volumen del agua. En segundo lugar, el aumento de las temperaturas está derritiendo los glaciares. Y por último, las enormes capas de hielo que cubren Groenlandia y la Antártida se están derritiendo más rápidamente. Hasta el más leve aumento del nivel del mar tendría efectos devastadores en los hábitats costeros, provocando erosiones destructivas, inundaciones de humedales, contaminación de acuíferos y suelos agrícolas, y pérdida de hábitats para peces, aves y plantas.

Climatología Extrema

El aumento de la temperatura oceánica también está relacionado con las climatologías extremas. El incremento de la temperatura de la superficie marina influye en los patrones meteorológicos y desplaza las precipitaciones. Algunas regiones pueden experimentar fuertes tempestades e inundaciones, mientras que otras sufren sequías e incendios forestales. Estos cambios dan lugar a huracanes y tifones que avanzan con lentitud descargando más y más agua de lluvia, y arrasando todo a su paso.

Si queremos equilibrar el planeta, nuestra forma de actuar debe cambiar.

Áreas Marinas Protegidas

Nuestro océano y su riqueza están amenazados por la acción humana a todos los niveles, pero tenemos soluciones de eficacia demostrada. Las áreas marinas protegidas (AMP) son una estrategia clave para sostener y restaurar los ecosistemas oceánicos. Las AMP son como parques nacionales del mar. Son una solución eficaz para restaurar la vida del océano y proporcionan grandes beneficios a los seres humanos, gracias a la prohibición de la sobrepesca y de otras actividades perjudiciales. Las AMP abordan tres grandes crisis de la humanidad: 1) la crisis de la biodiversidad, 2) la seguridad alimentaria y 3) el cambio climático.

Cómo nos Protegen las AMP

Bien concebidas, las AMP pueden salvaguardar hábitats esenciales, como son los criaderos y las zonas de alimentación y reproducción. Protegen los ecosistemas vulnerables y las especies en peligro y ayudan a mantener redes alimentarias funcionales.

Las AMP son herramientas eficaces para restaurar la biodiversidad del océano y sus ecosistemas, y generan resiliencia ante desastres naturales asociados al calentamiento global. Al protegerlas, estas zonas se recuperan mucho más rápido que si no lo estuvieran.

Las reservas marinas mejoran el rendimiento de las pesquerías, y la seguridad económica de quienes dependen del océano para su subsistencia. Además, custodian las reservas marinas de carbono y mantienen las economías y comunidades costeras. También generan oportunidades para el ocio y el turismo, la investigación y la educación. Las áreas de importancia cultural e histórica, como las de los pueblos indígenas, los yacimientos arqueológicos o los pecios de naufragios, suelen incluirse en las áreas marinas protegidas. Las AMP ayudan a reponer los caladeros adyacentes con el sobrante de larvas y ejemplares adultos.

Problemas Oceánicos

• La sobrepesca y el calentamiento están esquilmando el océano y llevándolo a un punto crítico
• Destrucción de arrecifes coralinos y otros hábitats por el calentamiento y acidificación del océano
• El 90 por ciento de los grandes peces han desaparecido del océano
• 82 por ciento: Porcentaje de pesquerías sobreexplotadas
• La crisis de biodiversidad del océano es una amenaza para la humanidad y para la economía

Las AMP Como Solución

• Las AMP restauran la biodiversidad del océano y benefician a la gente
• 600 por ciento: Las AMP reponen bancos de peces y generan seguridad alimentaria
• Incremento medio de biomasa piscícola en AMPs de protección integral
• Las AMP capturan carbono y mejoran la resiliencia ante el cambio climático
• 30 por ciento: Superficie de océano que se pretende proteger para 2030

La unión internacional para la conservación de la naturaleza (uicn) afirma que las amp son “espacios geográficos bien definidos, reconocidos, dedicados y manejados por medios legales y mecanismos eficaces de conservación de la naturaleza, y de sus valores ecosistémicos y culturales, a largo plazo.”

Niveles de Protección

No todas las AMP han sido concebidas de la misma manera.

AMP de protección integral › No se permite la prospección o explotación minera; ni canalizaciones activas con riesgo de fuga; ni dragados o vertidos. Sólo se permiten fondeaderos a pequeña escala, de corta duración y bajo impacto; infraestructuras menores y de impacto mínimo con fines de conservación, científicos, de navegación o de turismo sostenible. Acuicultura, solo a efectos de restauración, no de extracción. No se permite la pesca de ningún tipo. Las actividades no extractivas se limitarán a un uso a pequeña escala, rigurosamente regulado y de bajo impacto (esnórquel, natación, submarinismo, charcas mareales), reuniones culturales o ceremoniales, educación cultural, enseñanza y trasmisión de conocimientos, y otros usos.

AMP de protección elevada › No se permite la prospección o explotación minera; ni canalizaciones con riesgo de fugas; ni dragados o vertidos. Sólo se permiten fondeaderos a pequeña escala, de corta duración y bajo impacto, infraestructuras menores y de bajo impacto (instalaciones de turismo sostenible, acuicultura, energía renovable y arrecifes artificiales). Acuicultura sólo a pequeña escala, de baja densidad y sin aporte de piensos. Se permite, de forma ocasional, la pesca con sólo cinco o menos tipos de aparejos, muy selectivos y de bajo impacto. Para las actividades no extractivas, sólo se permite un uso a pequeña escala, rigurosamente regulado y de bajo impacto (esnórquel, natación, submarinismo, charcas mareales), reuniones culturales o ceremoniales, educación cultural, enseñanza y trasmisión de conocimientos y otros usos.

AMP de protección limitada › No se permite la prospección o explotación minera; ni canalizaciones con riesgo de fugas; ni dragados o vertidos. Se permiten dragados para navegación, restauración, protección del litoral y la erosión y seguridad costeras; el anclaje moderado no regulado; el anclaje en hábitats vulnerables, poco tiempo. Algunas de las estructuras permitidas son: instalaciones de impacto moderado de turismo sostenible y la acuicultura; estructuras de energía renovable y arrecifes artificiales (puede permitirse la pesca). Se permite la acuicultura sin piensos a escala comercial, de semiintensiva a intensiva; la acuicultura con piensos a pequeña escala y de baja densidad y la acuicultura de baja densidad, a pequeña escala y tradicional (peces, camarones). Se permite la pesca pero con una cantidad moderada de aparejos (diez o menos). Están permitidas las actividades no extractivas sin regulación o de alto impacto, de alta densidad y a gran escala.

AMP de protección mínima › No se permite la minería, la prospección o la explotación. Tampoco las canalizaciones activas con riesgo de fuga. Se permiten dragados para navegación, restauración, protección del litoral y la erosión y seguridad costeras. Se permite el anclaje de gran impacto cuando es compatible con los objetivos de conservación de la biodiversidad, así como infraestructuras de gran impacto en las mismas condiciones. Se permite la acuicultura con piensos a escala comercial y semiintensiva, y en hábitats vulnerables o cerca de ellos. Se permite la pesca con un número elevado (más de diez) de tipos de aparejos de gran impacto, pero no industriales, y las actividades no extractivas de alto impacto, alta densidad y a gran escala.

A mayor nivel de protección, mejores resultados de conservación.

Alcance y escala

Actualmente hay más de 16,000 amp en todo el mundo. Aunque parezca una cifra elevada, sólo cubren alrededor de un 8 por ciento de nuestro océano. Y menos del 3 por ciento está en una amp de protección integral o elevada.

363 Millones de km2: Área aproximada del océano

29 Millones de km2: Área total protegida del océano (algo más que las superficies de rusia y canadá juntas)

8.8 Millones de km2: Área total de las amp de protección elevada o integral (algo menos que la superficie de estados unidos)

Las amp generan:

• Mayores cantidades de peces
• Peces de mayor tamaño
• Mayor diversidad de especies
• Protección de reservas de carbono
• Respeto por las tradiciones y prácticas culturales
• Oportunidades de aprendizaje
• Mayor seguridad laboral y alimentaria
• Economías basadas en el turismo
• Ocio y diversión

Más de 100 países han acordado alcanzar el objetivo de proteger al menos el 30 por ciento del océano en 2030 siguiendo criterios científicos.

Las áreas marinas protegidas:

1 › Recuperan la vida marina tras una década de protección integral las poblaciones de peces aumentaron un 600 por ciento.

2 › Mejoran la pesca los peces desbordan los límites de la reserva y ayudan a reponer los caladeros adyacentes. En california, los pescadores locales capturan un 225 % más de langostas tras proteger el 35 % de sus caladeros, sólo seis años después de la creación del amp.

3 › Generan turismo de buceo cuando los peces regresan, los submarinistas también. En las islas medes, el buceo emplea a cientos de personas y aporta 12 millones de euros al año, 24 veces más que la pesca.

4 › Mitigan el calentamiento global la protección de los sedimentos de carbono evita emisiones de dióxido de carbono similares a las de la aviación mundial, con lo que se contribuye a frenar el calentamiento global.

5 › Aumentan los beneficios globales estimulan la producción de oxígeno. Este fenómeno tiene impacto a escala global, ya que toda la vida está relacionada con el océano.

Pristine Seas de National Geographic

El biólogo Enric Sala pensó que, como científico académico, lo único que hacía era escribir el obituario del océano. Así que en 2008 abandonó la enseñanza para dedicar su vida a la conservación como Explorador en residencia de National Geographic. Sala era profesor en el Instituto Scripps de océanografía de California cuando decidió trabajar más activamente en la protección del océano, y en la recuperación de su riqueza y diversidad, para contrarrestar el declive que él mismo estaba documentando.

Pristine Seas es la gran iniciativa de conservación de National Geographic Society. Protege zonas vitales del océano mediante la exploración, la investigación, los medios, la economía, la comunicación y la política, junto a comunidades locales, pueblos indígenas y gobiernos.

Cómo se Trabaja

Se tarda meses en planificar una expedición de Pristine Seas. Expertos y participantes locales de diversas disciplinas se unen para documentar y evaluar la biodiversidad de una zona determinada. Los datos recogidos durante la expedición se comparten con la comunidad científica, gobiernos, comunidades locales y miembros de Pristine Seas para informar de la necesidad de crear un AMP y de su diseño. Las prácticas tradicionales de conservación locales e indígenas –vigentes a veces durante siglos–ofrecen modelos clave para el equipo de Pristine Seas.

Hasta ahora, pristine seas ha realizado 36 expediciones en más de 20 países y ha trabajado con las comunidades locales en la creación de 25 de las mayores reservas marinas de la tierra. Estas amp cubren más de 6.5 Millones de kilómetros cuadrados —una extensión equivalente a dos tercios de los estados unidos—, donde la vida marina florece y repone las aguas adyancentes.

Pristine seas trabajará con comunidades, gobiernos y otros colaboradores en la creación de nuevas amp para proteger al menos un 30 porciento del océano para el año 2030.

AMP en Marcha: La Viva Vuelve a Cabo Pulmo

Juan Castro Montaño recuerda cuántos peces había en el mexicano Cabo Pulmo durante su niñez. “La pesca era muy importante, era el medio de vida de esta comunidad”, dice. La pesca comercial alcanzó tal desarrollo que se hizo insostenible. Al ver que las capturas de peces estaban cayendo, los pobladores locales hicieron algo extraordinario. En 1995, pidieron al gobierno mexicano que creará un parque nacional marino en su arrecife para recuperarlo. No fue una decisión fácil. Implicaba que las personas que vivían de la pesca tendrían que buscar otra forma de ganarse la vida.

“Dejamos de pescar de un día para otro”, dice el pescador Mario Castro Lucero. “Ahora nos dedicamos al ecoturismo. Fue difícilísimo, pero lo hemos logrado. Era la manera de preservar el arrecife y de ganarse la vida de otra forma”.

Los resultados fueron asombrosos. El Parque Nacional Marino Cabo Pulmo ha experimentado la mayor recuperación jamás observada en un área marina protegida. En 10 años, la población de peces aumentó en más del 460 por ciento, lo que llevó al arrecife a un nivel de biomasa (conjunto de materia viva) similar al de un arrecife en el que jamás se ha pescado. “Creo que si mi papá y mi abuelo vieran el arrecife así, dirían: ‘Resucitó. Toda esa riqueza que teníamos de niños ha regresado; ellos se sentirían muy orgullosos”, comenta Mario.

Juan está de acuerdo. “Otras generaciones podrán verlo cuando nosotros faltemos. Ahora nos toca ser los centinelas que vigilan el arrecife y cuidan de él”.

Cabo Pulmo pasó a ser un modelo para Pristine Seas.

AMP en Marcha: Proteger la Biodiversidad

Al norte de Madagascar, en el Océano Índico occidental, está el archipiélago de las Seychelles formado por 115 islas. Aldabra, uno de los mayores atolones coralinos del mundo, es Patrimonio de la Humanidad desde 1982.

El Papel de Pristine Seas

Durante 200 horas de sondeos en 39 puntos diferentes, el equipo de Pristine Seas evaluó la biodiversidad de las Islas Exteriores de las Seychelles. Vieron que las aguas de las islas estaban rebosantes de vida. Con el apoyo de funcionarios locales y de organizaciones sin fines de lucro, el equipo recopiló datos para proponer la creación de grandes zonas vedadas a la pesca en torno a las Islas Exteriores. Esta información fue reportada al gobierno de Seychelles, que creó un AMP de protección elevada de 74,400 kilómetros cuadrados. Esta AMP cubre el 10 por ciento de las aguas territoriales de las Seychelles.

Voces de la Conservación: Alvania Lawen, Islas Seychelles

Para Alvania Lawen, una joven defensora de los océanos, la protección de las islas Seychelles es algo personal:

“La vida en las Seychelles está ligada al océano. Proteger los océanos es algo que me sale del alma. Mi trabajo de conservación empezó a los 11 años cuando empecé a hacer esnórquel y descubrí nuestra biodiversidad. Luego me apunté a una campaña para prohibir ciertos plásticos de un solo uso orquestada por las organizaciones no gubernamentales (ONG) Sustainability for Seychelles y SYAH-Seychelles. Abogué activamente por alternativas al plástico. Gracias a nuestra labor, en 2017 conseguimos que se prohibiera la importación y distribución de bolsas y vasos de plástico.

Nuestra economía se basa en el turismo, un sector que depende en gran medida de los ecosistemas marinos. El término economía azul alude al uso económico sostenible del océano. Las ONG juegan un papel importante en la protección medioambiental; yo pertenezco a varias ONG medioambientales dirigidas por mujeres y jóvenes.

Los jóvenes como yo podemos marcar la diferencia y usar las redes sociales para proteger el océano. No hace falta ser una estrella de Instagram o tener millones de seguidores; solo debes tener claros tus objetivos y conectar con personas y organizaciones que compartan tu misión. Trata de convertir la información negativa, como las noticias alarmantes sobre el cambio climático, en una motivación para persistir en tu labor”.

AMP en Marcha: La Resiliencia de la Naturaleza

En lo más remoto del Pacífico, hay una cadena de islas y atolones coralinos a ambos lados del ecuador: las Islas de la Línea. Estas motas de tierra, pertenecientes a la república de Kiribati, son uno de los atolones más aislados de la Tierra. Están desiertos y apenas son visitados.

En 2009 los buzos pasaron más de mil horas bajo el agua entre las cinco islas. Su hallazgo les dejó boquiabiertos. En algunos arrecifes, los corales eran tan densos que cubrían el 90 por ciento del lecho marino, muchísimo más que el promedio de la cubierta coralina del Caribe, que es de menos del 10 por ciento.

En algunas partes de la laguna de la isla Caroline (atolón del Milenio), la densidad de almejas gigantes es de hasta cuatro por pie cuadrado, una abundancia casi inaudita para una especie tan buscada por su carne y sus conchas. Estos enormes filtradores actúan como depuradoras de agua, limpiándola de bacterias nocivas para corales, peces, moluscos y crustáceos.

En 2015, las averiguaciones de Pristine Seas llevaron al gobierno de Kiribati a delimitar una zona de 12 millas náuticas en torno a las islas de la Línea, que quedaron cerradas a la pesca comercial. La zona quedó protegida con el fin de mantenerla en su estado prístino.

Y entonces llegó el desastre. Los picos de calor causados en 2016 por la corriente de El Niño en todo el Pacífico, arrasaron grandes extensiones de coral. Pristine Seas volvió en 2021 esperando encontrar un paisaje desolado. Pero las islas de la Línea tuvieron una recuperación espectacular. ¿Cómo lo lograron? Los corales son resilientes allí donde hay otros elementos pujantes del ecosistema marino. Los abundantísimos peces de las islas de la Línea limpiaron los esqueletos de coral de algas y crearon las condiciones necesarias para que crecieran de nuevo. Gracias a su estatus de protección, este lugar demostró tener una gran resiliencia ante un desastre.

AMP en Marcha: Soluciones Indígenas

El Parque Nacional Kawésqar es de los más extensos del mundo y el segundo parque terrestre más grande de Chile. Los bosques de algas del sur de Chile están entre los más sanos de la Tierra.

A principios de 2020, Pristine Seas organizó una expedición a los fiordos patagónicos con las comunidades indígenas locales kawésqar y yagan. El área explorada está amenazada por la acuicultura intensiva de salmón, que se ha convertido en una importante industria en Chile. Lamentablemente, esta actividad tiene graves impactos ambientales, higiénicos y sociales. El equipo estudió a fondo los ecosistemas costeros y de aguas profundas, y aprendió de las comunidades kawésqar y yagan acerca del significado cultural y ecológico de la región. Pristine Seas está apoyando a estas comunidades para mantener su cultura viva y obtener la plena protección de sus territorios y, con ellos, de su identidad, cosmovisión, subsistencia y derechos ancestrales. El equipo elaboró un completo informe científico y cultural de la expedición y rodó un documental sobre este viaje.

Qué Puedes Hacer

Proteger nuestro océano y devolverle su plenitud e integridad es una gran tarea. No hay una única solución, pero son muchas las cosas que podemos hacer, individual y colectivamente, para ayudar.

• Recuerda que la tierra y el mar están conectados. Visita áreas marinas protegidas, costas, ríos o lagos locales donde hacer esnórquel o conectar con la Naturaleza.
• Boicotea la pesca insostenible. Si no es sostenible, no te lo comas. Que la etiqueta diga pescado a caña o por buceo.
• Reduce tu huella de carbono. Usa menos combustibles fósiles. No uses tanto el auto y viaja en transporte público. Compra electrodomésticos de bajo consumo y aprovecha los programas de energía solar.
• Reduce la basura que generas.
• Reutiliza todo lo que puedas. Elige productos reutilizables en lugar de desechables y recicla. No uses bolsas de plástico. Compra ropa de segunda mano. Ahorra agua. El agua dulce es un recurso limitado y escaso en muchas partes del mundo. Al utilizar menos agua, se reducen las escorrentías y las aguas residuales que se vierten al océano.
• Hazte voluntario. Los grupos conservacionistas necesitan tu ayuda.
• Organiza o participa en recogidas de basuras. Si ayudamos a recoger la basura de nuestras calles, ríos, arroyos o playas, podemos evitar que acabe en el mar.
• Planta árboles. Nuestros bosques ayudan a reducir el dióxido de carbono en la atmósfera, aliviando la presión sobre nuestro océano.
• Lleva una dieta rica en verduras. Compra alimentos locales para reducir las emisiones del transporte y la producción.
• ¡Ojo con qué tiras al inodoro! No botes al inodoro detergentes, pesticidas, desatascadores y arena para gatos, ya que estos productos químicos pueden filtrarse a nuestros ríos y lagos, y llegar al océano.
• Sigue al Explorador Enric Sala y a Pristine Seas en redes sociales para estar informado de sus trabajos por todo el mundo. twitter.com/Enric_Sala instagram.com/enricsala/
• Aprende primero y luego enseña. Cuando entendemos cómo funcionan los ecosistemas, podemos tomar medidas para protegerlos. Aprende lo que puedas y compártelo para crear una conciencia colectiva.
• Habla sin miedo. Defiende el cambio que quieres ver en tu comunidad y en el mundo.

Mueve a la Acción

¿Qué puedes hacer en tu comunidad? Después de leer este manual y de ver algunas de las sugerencias de la página 30, crea un plan de acción personal para ayudar a conservar el océano.

Hazte algunas importantes preguntas:

1 › ¿Cuál sería la mejor manera de promover la conservación del océano desde tu comunidad?

2 › ¿Cuáles son las ventajas de esta acción o solución?

3 › ¿Se te ocurre algún inconveniente?

4 › ¿Qué más necesitas saber o investigar para crear un plan integral?

5 › Haz una lista de todas las partes de tu plan. ¿Qué harás primero? ¿Cuál es el paso siguiente?

6 › ¿Es un plan que puedes llevar a cabo tú solo o necesitarás ayuda?

7 › Enumera algunas personas o grupos que pudieran apoyar tu idea.

8 › ¿Cómo te dirigirías a estas personas o grupos para que colaboren en tu plan?

9 › Elabora un calendario para tu plan. ¿Cuánto tiempo te llevará hacer cada parte?

10 › Comparte tu plan con otras personas y pide su opinión.

11 › Adapta tu plan en función de los comentarios recibidos.

12 › ¡Cuando el plan esté listo, actúa!

¿Qué Maás Quieres Saber?

Si quieres saber más sobre nuestro océano, las amenazas que se ciernen sobre él y cómo ayudar, puedes consultar estos recursos:

Para Educadores

• Cursos de aprendizaje profesional
• One Ocean Educator Guide (para aprendizaje profesional)
• Earth Day 2021 Guide (centrada en el océano)

Para Estudiantes

Ciencia ciudadana

• iNaturalist: inaturalist.org y Seek: inaturalist.org/pages/seek_app

Creación de mapas:

Recursos Fuera de Línea

Esta sección incluye ejemplos de recursos que podrían descargarse o transmitirse a comunidades sin acceso a Internet o con una conexión débil. Muchos de estos recursos pueden imprimirse o descargarse en PDF o archivos comprimidos (zip). Busca los iconos de cada recurso junto a los iconos de las redes sociales, normalmente justo debajo de la foto del recurso.

› Cadenas alimentarias marinas Los estudiantes utilizan tarjetas de organismos marinos y tipos de niveles tróficos para identificar y describir las cadenas alimentarias de varios ecosistemas marinos. Descarga el archivo comprimido que contiene múltiples PDF en bit.ly/3CsNQbj

› Pesca sostenible : Una entrada enciclopédica clasificada que plantea el tema y define los términos clave. Se puede imprimir o guardar en PDF en

› Proteger el océano Los estudiantes hablan sobre “quién es el dueño del océano” y trabajan en pequeños grupos para explorar cuestiones sobre la utilización del medio marino. Luego, miran videos y comentan conceptos relacionados con la creación y designación de las Áreas Marinas Protegidas (AMP). Descarga el archivo comprimido con dos PDF en bit.ly/3yFiIEa

› Nuestro océano interconectado Los estudiantes analizan la geografía del océano y exploran cómo se ha estudiado en el pasado y en la actualidad. Descarga los PDF en bit.ly/3CVU4Sm

› Gestión de áreas marinas protegidas Los estudiantes leen un estudio de caso y debaten sobre los pros y los contras de un área marina protegida (AMP) de la región. A continuación, seleccionan un AMP y elaboran y presentan un plan de gestión. Descarga los archivos comprimidos que contienen múltiples PDF en bit.ly/3RVdxH3

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Last Updated

April 1, 2024

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service .

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

• Search Menu
• Browse content in Arts and Humanities
• Browse content in Archaeology
• Anglo-Saxon and Medieval Archaeology
• Archaeological Methodology and Techniques
• Archaeology by Region
• Archaeology of Religion
• Archaeology of Trade and Exchange
• Biblical Archaeology
• Contemporary and Public Archaeology
• Environmental Archaeology
• Historical Archaeology
• History and Theory of Archaeology
• Industrial Archaeology
• Landscape Archaeology
• Mortuary Archaeology
• Prehistoric Archaeology
• Underwater Archaeology
• Urban Archaeology
• Zooarchaeology
• Browse content in Architecture
• Architectural Structure and Design
• History of Architecture
• Residential and Domestic Buildings
• Theory of Architecture
• Browse content in Art
• Art Subjects and Themes
• History of Art
• Industrial and Commercial Art
• Theory of Art
• Biographical Studies
• Byzantine Studies
• Browse content in Classical Studies
• Classical History
• Classical Philosophy
• Classical Mythology
• Classical Literature
• Classical Reception
• Classical Art and Architecture
• Classical Oratory and Rhetoric
• Greek and Roman Epigraphy
• Greek and Roman Law
• Greek and Roman Papyrology
• Greek and Roman Archaeology
• Late Antiquity
• Religion in the Ancient World
• Digital Humanities
• Browse content in History
• Colonialism and Imperialism
• Diplomatic History
• Environmental History
• Genealogy, Heraldry, Names, and Honours
• Genocide and Ethnic Cleansing
• Historical Geography
• History by Period
• History of Emotions
• History of Agriculture
• History of Education
• History of Gender and Sexuality
• Industrial History
• Intellectual History
• International History
• Labour History
• Legal and Constitutional History
• Local and Family History
• Maritime History
• Military History
• National Liberation and Post-Colonialism
• Oral History
• Political History
• Public History
• Regional and National History
• Revolutions and Rebellions
• Slavery and Abolition of Slavery
• Social and Cultural History
• Theory, Methods, and Historiography
• Urban History
• World History
• Browse content in Language Teaching and Learning
• Language Learning (Specific Skills)
• Language Teaching Theory and Methods
• Browse content in Linguistics
• Applied Linguistics
• Cognitive Linguistics
• Computational Linguistics
• Forensic Linguistics
• Grammar, Syntax and Morphology
• Historical and Diachronic Linguistics
• History of English
• Language Acquisition
• Language Evolution
• Language Reference
• Language Variation
• Language Families
• Lexicography
• Linguistic Anthropology
• Linguistic Theories
• Linguistic Typology
• Phonetics and Phonology
• Psycholinguistics
• Sociolinguistics
• Translation and Interpretation
• Writing Systems
• Browse content in Literature
• Bibliography
• Children's Literature Studies
• Literary Studies (Asian)
• Literary Studies (European)
• Literary Studies (Eco-criticism)
• Literary Studies (Romanticism)
• Literary Studies (American)
• Literary Studies (Modernism)
• Literary Studies - World
• Literary Studies (1500 to 1800)
• Literary Studies (19th Century)
• Literary Studies (20th Century onwards)
• Literary Studies (African American Literature)
• Literary Studies (British and Irish)
• Literary Studies (Early and Medieval)
• Literary Studies (Fiction, Novelists, and Prose Writers)
• Literary Studies (Gender Studies)
• Literary Studies (Graphic Novels)
• Literary Studies (History of the Book)
• Literary Studies (Plays and Playwrights)
• Literary Studies (Poetry and Poets)
• Literary Studies (Postcolonial Literature)
• Literary Studies (Queer Studies)
• Literary Studies (Science Fiction)
• Literary Studies (Travel Literature)
• Literary Studies (War Literature)
• Literary Studies (Women's Writing)
• Literary Theory and Cultural Studies
• Mythology and Folklore
• Shakespeare Studies and Criticism
• Browse content in Media Studies
• Browse content in Music
• Applied Music
• Dance and Music
• Ethics in Music
• Ethnomusicology
• Gender and Sexuality in Music
• Medicine and Music
• Music Cultures
• Music and Religion
• Music and Media
• Music and Culture
• Music Education and Pedagogy
• Music Theory and Analysis
• Musical Scores, Lyrics, and Libretti
• Musical Structures, Styles, and Techniques
• Musicology and Music History
• Performance Practice and Studies
• Race and Ethnicity in Music
• Sound Studies
• Browse content in Performing Arts
• Browse content in Philosophy
• Aesthetics and Philosophy of Art
• Epistemology
• Feminist Philosophy
• History of Western Philosophy
• Metaphysics
• Moral Philosophy
• Non-Western Philosophy
• Philosophy of Science
• Philosophy of Language
• Philosophy of Mind
• Philosophy of Perception
• Philosophy of Action
• Philosophy of Law
• Philosophy of Religion
• Philosophy of Mathematics and Logic
• Practical Ethics
• Social and Political Philosophy
• Browse content in Religion
• Biblical Studies
• Christianity
• East Asian Religions
• History of Religion
• Judaism and Jewish Studies
• Qumran Studies
• Religion and Education
• Religion and Health
• Religion and Politics
• Religion and Science
• Religion and Law
• Religion and Art, Literature, and Music
• Religious Studies
• Browse content in Society and Culture
• Cookery, Food, and Drink
• Cultural Studies
• Customs and Traditions
• Ethical Issues and Debates
• Hobbies, Games, Arts and Crafts
• Lifestyle, Home, and Garden
• Natural world, Country Life, and Pets
• Popular Beliefs and Controversial Knowledge
• Sports and Outdoor Recreation
• Technology and Society
• Travel and Holiday
• Visual Culture
• Browse content in Law
• Arbitration
• Browse content in Company and Commercial Law
• Commercial Law
• Company Law
• Browse content in Comparative Law
• Systems of Law
• Competition Law
• Browse content in Constitutional and Administrative Law
• Government Powers
• Judicial Review
• Local Government Law
• Military and Defence Law
• Parliamentary and Legislative Practice
• Construction Law
• Contract Law
• Browse content in Criminal Law
• Criminal Procedure
• Criminal Evidence Law
• Sentencing and Punishment
• Employment and Labour Law
• Environment and Energy Law
• Browse content in Financial Law
• Banking Law
• Insolvency Law
• History of Law
• Human Rights and Immigration
• Intellectual Property Law
• Browse content in International Law
• Private International Law and Conflict of Laws
• Public International Law
• IT and Communications Law
• Jurisprudence and Philosophy of Law
• Law and Politics
• Law and Society
• Browse content in Legal System and Practice
• Courts and Procedure
• Legal Skills and Practice
• Primary Sources of Law
• Regulation of Legal Profession
• Medical and Healthcare Law
• Browse content in Policing
• Criminal Investigation and Detection
• Police and Security Services
• Police Procedure and Law
• Police Regional Planning
• Browse content in Property Law
• Personal Property Law
• Study and Revision
• Terrorism and National Security Law
• Browse content in Trusts Law
• Wills and Probate or Succession
• Browse content in Medicine and Health
• Browse content in Allied Health Professions
• Arts Therapies
• Clinical Science
• Dietetics and Nutrition
• Occupational Therapy
• Operating Department Practice
• Physiotherapy
• Radiography
• Speech and Language Therapy
• Browse content in Anaesthetics
• General Anaesthesia
• Neuroanaesthesia
• Browse content in Clinical Medicine
• Acute Medicine
• Cardiovascular Medicine
• Clinical Genetics
• Clinical Pharmacology and Therapeutics
• Dermatology
• Endocrinology and Diabetes
• Gastroenterology
• Genito-urinary Medicine
• Geriatric Medicine
• Infectious Diseases
• Medical Toxicology
• Medical Oncology
• Pain Medicine
• Palliative Medicine
• Rehabilitation Medicine
• Respiratory Medicine and Pulmonology
• Rheumatology
• Sleep Medicine
• Sports and Exercise Medicine
• Clinical Neuroscience
• Community Medical Services
• Critical Care
• Emergency Medicine
• Forensic Medicine
• Haematology
• History of Medicine
• Browse content in Medical Dentistry
• Oral and Maxillofacial Surgery
• Paediatric Dentistry
• Restorative Dentistry and Orthodontics
• Surgical Dentistry
• Browse content in Medical Skills
• Clinical Skills
• Communication Skills
• Nursing Skills
• Surgical Skills
• Medical Ethics
• Medical Statistics and Methodology
• Browse content in Neurology
• Clinical Neurophysiology
• Neuropathology
• Nursing Studies
• Browse content in Obstetrics and Gynaecology
• Gynaecology
• Occupational Medicine
• Ophthalmology
• Otolaryngology (ENT)
• Browse content in Paediatrics
• Neonatology
• Browse content in Pathology
• Chemical Pathology
• Clinical Cytogenetics and Molecular Genetics
• Histopathology
• Medical Microbiology and Virology
• Patient Education and Information
• Browse content in Pharmacology
• Psychopharmacology
• Browse content in Popular Health
• Caring for Others
• Complementary and Alternative Medicine
• Self-help and Personal Development
• Browse content in Preclinical Medicine
• Cell Biology
• Molecular Biology and Genetics
• Reproduction, Growth and Development
• Primary Care
• Professional Development in Medicine
• Browse content in Psychiatry
• Addiction Medicine
• Child and Adolescent Psychiatry
• Forensic Psychiatry
• Learning Disabilities
• Old Age Psychiatry
• Psychotherapy
• Browse content in Public Health and Epidemiology
• Epidemiology
• Public Health
• Browse content in Radiology
• Clinical Radiology
• Interventional Radiology
• Nuclear Medicine
• Radiation Oncology
• Reproductive Medicine
• Browse content in Surgery
• Cardiothoracic Surgery
• Gastro-intestinal and Colorectal Surgery
• General Surgery
• Neurosurgery
• Paediatric Surgery
• Peri-operative Care
• Plastic and Reconstructive Surgery
• Surgical Oncology
• Transplant Surgery
• Trauma and Orthopaedic Surgery
• Vascular Surgery
• Browse content in Science and Mathematics
• Browse content in Biological Sciences
• Aquatic Biology
• Biochemistry
• Bioinformatics and Computational Biology
• Developmental Biology
• Ecology and Conservation
• Evolutionary Biology
• Genetics and Genomics
• Microbiology
• Molecular and Cell Biology
• Natural History
• Plant Sciences and Forestry
• Research Methods in Life Sciences
• Structural Biology
• Systems Biology
• Zoology and Animal Sciences
• Browse content in Chemistry
• Analytical Chemistry
• Computational Chemistry
• Crystallography
• Environmental Chemistry
• Industrial Chemistry
• Inorganic Chemistry
• Materials Chemistry
• Medicinal Chemistry
• Mineralogy and Gems
• Organic Chemistry
• Physical Chemistry
• Polymer Chemistry
• Study and Communication Skills in Chemistry
• Theoretical Chemistry
• Browse content in Computer Science
• Artificial Intelligence
• Computer Architecture and Logic Design
• Game Studies
• Human-Computer Interaction
• Mathematical Theory of Computation
• Programming Languages
• Software Engineering
• Systems Analysis and Design
• Virtual Reality
• Browse content in Computing
• Business Applications
• Computer Security
• Computer Games
• Computer Networking and Communications
• Digital Lifestyle
• Graphical and Digital Media Applications
• Operating Systems
• Browse content in Earth Sciences and Geography
• Atmospheric Sciences
• Environmental Geography
• Geology and the Lithosphere
• Maps and Map-making
• Meteorology and Climatology
• Oceanography and Hydrology
• Palaeontology
• Physical Geography and Topography
• Regional Geography
• Soil Science
• Urban Geography
• Browse content in Engineering and Technology
• Agriculture and Farming
• Biological Engineering
• Civil Engineering, Surveying, and Building
• Electronics and Communications Engineering
• Energy Technology
• Engineering (General)
• Environmental Science, Engineering, and Technology
• History of Engineering and Technology
• Mechanical Engineering and Materials
• Technology of Industrial Chemistry
• Transport Technology and Trades
• Browse content in Environmental Science
• Applied Ecology (Environmental Science)
• Conservation of the Environment (Environmental Science)
• Environmental Sustainability
• Environmentalist Thought and Ideology (Environmental Science)
• Management of Land and Natural Resources (Environmental Science)
• Natural Disasters (Environmental Science)
• Nuclear Issues (Environmental Science)
• Pollution and Threats to the Environment (Environmental Science)
• Social Impact of Environmental Issues (Environmental Science)
• History of Science and Technology
• Browse content in Materials Science
• Ceramics and Glasses
• Composite Materials
• Metals, Alloying, and Corrosion
• Nanotechnology
• Browse content in Mathematics
• Applied Mathematics
• Biomathematics and Statistics
• History of Mathematics
• Mathematical Education
• Mathematical Finance
• Mathematical Analysis
• Numerical and Computational Mathematics
• Probability and Statistics
• Pure Mathematics
• Browse content in Neuroscience
• Cognition and Behavioural Neuroscience
• Development of the Nervous System
• Disorders of the Nervous System
• History of Neuroscience
• Invertebrate Neurobiology
• Molecular and Cellular Systems
• Neuroendocrinology and Autonomic Nervous System
• Neuroscientific Techniques
• Sensory and Motor Systems
• Browse content in Physics
• Astronomy and Astrophysics
• Atomic, Molecular, and Optical Physics
• Biological and Medical Physics
• Classical Mechanics
• Computational Physics
• Condensed Matter Physics
• Electromagnetism, Optics, and Acoustics
• History of Physics
• Mathematical and Statistical Physics
• Measurement Science
• Nuclear Physics
• Particles and Fields
• Plasma Physics
• Quantum Physics
• Relativity and Gravitation
• Semiconductor and Mesoscopic Physics
• Browse content in Psychology
• Affective Sciences
• Clinical Psychology
• Cognitive Psychology
• Cognitive Neuroscience
• Criminal and Forensic Psychology
• Developmental Psychology
• Educational Psychology
• Evolutionary Psychology
• Health Psychology
• History and Systems in Psychology
• Music Psychology
• Neuropsychology
• Organizational Psychology
• Psychological Assessment and Testing
• Psychology of Human-Technology Interaction
• Psychology Professional Development and Training
• Research Methods in Psychology
• Social Psychology
• Browse content in Social Sciences
• Browse content in Anthropology
• Anthropology of Religion
• Human Evolution
• Medical Anthropology
• Physical Anthropology
• Regional Anthropology
• Social and Cultural Anthropology
• Theory and Practice of Anthropology
• Browse content in Business and Management
• Business Strategy
• Business Ethics
• Business History
• Business and Government
• Business and Technology
• Business and the Environment
• Comparative Management
• Corporate Governance
• Corporate Social Responsibility
• Entrepreneurship
• Health Management
• Human Resource Management
• Industrial and Employment Relations
• Industry Studies
• Information and Communication Technologies
• International Business
• Knowledge Management
• Management and Management Techniques
• Operations Management
• Organizational Theory and Behaviour
• Pensions and Pension Management
• Public and Nonprofit Management
• Strategic Management
• Supply Chain Management
• Browse content in Criminology and Criminal Justice
• Criminal Justice
• Criminology
• Forms of Crime
• International and Comparative Criminology
• Youth Violence and Juvenile Justice
• Development Studies
• Browse content in Economics
• Agricultural, Environmental, and Natural Resource Economics
• Asian Economics
• Behavioural Finance
• Behavioural Economics and Neuroeconomics
• Econometrics and Mathematical Economics
• Economic Systems
• Economic History
• Economic Methodology
• Economic Development and Growth
• Financial Markets
• Financial Institutions and Services
• General Economics and Teaching
• Health, Education, and Welfare
• History of Economic Thought
• International Economics
• Labour and Demographic Economics
• Law and Economics
• Macroeconomics and Monetary Economics
• Microeconomics
• Public Economics
• Urban, Rural, and Regional Economics
• Welfare Economics
• Browse content in Education
• Adult Education and Continuous Learning
• Care and Counselling of Students
• Early Childhood and Elementary Education
• Educational Equipment and Technology
• Educational Strategies and Policy
• Higher and Further Education
• Organization and Management of Education
• Philosophy and Theory of Education
• Schools Studies
• Secondary Education
• Teaching of a Specific Subject
• Teaching of Specific Groups and Special Educational Needs
• Teaching Skills and Techniques
• Browse content in Environment
• Applied Ecology (Social Science)
• Climate Change
• Conservation of the Environment (Social Science)
• Environmentalist Thought and Ideology (Social Science)
• Natural Disasters (Environment)
• Social Impact of Environmental Issues (Social Science)
• Browse content in Human Geography
• Cultural Geography
• Economic Geography
• Political Geography
• Browse content in Interdisciplinary Studies
• Communication Studies
• Museums, Libraries, and Information Sciences
• Browse content in Politics
• African Politics
• Asian Politics
• Chinese Politics
• Comparative Politics
• Conflict Politics
• Elections and Electoral Studies
• Environmental Politics
• European Union
• Foreign Policy
• Gender and Politics
• Human Rights and Politics
• Indian Politics
• International Relations
• International Organization (Politics)
• International Political Economy
• Irish Politics
• Latin American Politics
• Middle Eastern Politics
• Political Methodology
• Political Communication
• Political Philosophy
• Political Sociology
• Political Behaviour
• Political Economy
• Political Institutions
• Political Theory
• Politics and Law
• Public Administration
• Public Policy
• Quantitative Political Methodology
• Regional Political Studies
• Russian Politics
• Security Studies
• State and Local Government
• UK Politics
• US Politics
• Browse content in Regional and Area Studies
• African Studies
• Asian Studies
• East Asian Studies
• Japanese Studies
• Latin American Studies
• Middle Eastern Studies
• Native American Studies
• Scottish Studies
• Browse content in Research and Information
• Research Methods
• Browse content in Social Work
• Addictions and Substance Misuse
• Adoption and Fostering
• Care of the Elderly
• Child and Adolescent Social Work
• Couple and Family Social Work
• Developmental and Physical Disabilities Social Work
• Direct Practice and Clinical Social Work
• Emergency Services
• Human Behaviour and the Social Environment
• International and Global Issues in Social Work
• Mental and Behavioural Health
• Social Justice and Human Rights
• Social Policy and Advocacy
• Social Work and Crime and Justice
• Social Work Macro Practice
• Social Work Practice Settings
• Social Work Research and Evidence-based Practice
• Welfare and Benefit Systems
• Browse content in Sociology
• Childhood Studies
• Community Development
• Comparative and Historical Sociology
• Economic Sociology
• Gender and Sexuality
• Gerontology and Ageing
• Health, Illness, and Medicine
• Marriage and the Family
• Migration Studies
• Occupations, Professions, and Work
• Organizations
• Population and Demography
• Race and Ethnicity
• Social Theory
• Social Movements and Social Change
• Social Research and Statistics
• Social Stratification, Inequality, and Mobility
• Sociology of Religion
• Sociology of Education
• Sport and Leisure
• Urban and Rural Studies
• Browse content in Warfare and Defence
• Defence Strategy, Planning, and Research
• Land Forces and Warfare
• Military Administration
• Military Life and Institutions
• Naval Forces and Warfare
• Other Warfare and Defence Issues
• Peace Studies and Conflict Resolution
• Weapons and Equipment

Marine Biology: A Very Short Introduction (1st edn)

A newer edition of this book is available.

• Cite Icon Cite
• Permissions Icon Permissions

Marine Biology: A Very Short Introduction looks at marine life and marine processes. The marine environment is the largest, most important, and most mysterious habitat on our planet. It contains more than 99 percent of the world's living space, produces half of its oxygen, plays a critical role in regulating its climate, and supports a remarkably diverse and exquisitely adapted array of life forms. As the 21st century progresses, human activities such as overfishing, coastal development, plastic pollution, oil spills, nutrient pollution, the spread of exotic species, and the emission of climate changing greenhouse gases are posing a significant threat to the marine environment and to many of its life forms.

Signed in as

Institutional accounts.

• Google Scholar Indexing
• GoogleCrawler [DO NOT DELETE]

Personal account

• Sign in with email/username & password
• Get email alerts
• Save searches
• Purchase content
• Activate your purchase/trial code

Institutional access

• Sign in with a library card Sign in with username/password Recommend to your librarian
• Institutional account management
• Get help with access

Access to content on Oxford Academic is often provided through institutional subscriptions and purchases. If you are a member of an institution with an active account, you may be able to access content in one of the following ways:

IP based access

Typically, access is provided across an institutional network to a range of IP addresses. This authentication occurs automatically, and it is not possible to sign out of an IP authenticated account.

Sign in through your institution

Choose this option to get remote access when outside your institution. Shibboleth/Open Athens technology is used to provide single sign-on between your institution’s website and Oxford Academic.

• Click Sign in through your institution.
• Select your institution from the list provided, which will take you to your institution's website to sign in.
• When on the institution site, please use the credentials provided by your institution. Do not use an Oxford Academic personal account.
• Following successful sign in, you will be returned to Oxford Academic.

If your institution is not listed or you cannot sign in to your institution’s website, please contact your librarian or administrator.

Sign in with a library card

Enter your library card number to sign in. If you cannot sign in, please contact your librarian.

Society Members

Society member access to a journal is achieved in one of the following ways:

Sign in through society site

Many societies offer single sign-on between the society website and Oxford Academic. If you see ‘Sign in through society site’ in the sign in pane within a journal:

• Click Sign in through society site.
• When on the society site, please use the credentials provided by that society. Do not use an Oxford Academic personal account.

If you do not have a society account or have forgotten your username or password, please contact your society.

Sign in using a personal account

Some societies use Oxford Academic personal accounts to provide access to their members. See below.

A personal account can be used to get email alerts, save searches, purchase content, and activate subscriptions.

Some societies use Oxford Academic personal accounts to provide access to their members.

Viewing your signed in accounts

Click the account icon in the top right to:

• View your signed in personal account and access account management features.
• View the institutional accounts that are providing access.

Signed in but can't access content

Oxford Academic is home to a wide variety of products. The institutional subscription may not cover the content that you are trying to access. If you believe you should have access to that content, please contact your librarian.

For librarians and administrators, your personal account also provides access to institutional account management. Here you will find options to view and activate subscriptions, manage institutional settings and access options, access usage statistics, and more.

Our books are available by subscription or purchase to libraries and institutions.

Blog article

• A lost opportunity for sustainable ocean management

External resource

• In the OUP print catalogue
• About Oxford Academic
• Publish journals with us
• University press partners
• What we publish
• New features  
• Open access
• Rights and permissions
• Accessibility
• Advertising
• Media enquiries
• Oxford University Press
• Oxford Languages
• University of Oxford

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide

• Copyright © 2024 Oxford University Press
• Cookie settings
• Cookie policy
• Privacy policy
• Legal notice

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Home — Essay Samples — Environment — Earth & Nature — Marine Life

Essays on Marine Life

Unveiling the secrets and potential of bioluminescent waters, abiotic factors affecting the atlantic ocean, made-to-order essay as fast as you need it.

Each essay is customized to cater to your unique preferences

+ experts online

The Safety of Swimming in Bioluminescent Waters

How aquatic life has been impacted by pollution, the global problem of marine noise pollution, law of the marine environment, let us write you an essay from scratch.

• 450+ experts on 30 subjects ready to help
• Custom essay delivered in as few as 3 hours

Microsoft Sank a Data Center in The Ocean

Understanding echinoderms as part of marine biology, individual case development on e-procurement on board merchant ships, overview of algae phytoplankton: characterisation, history, application, get a personalized essay in under 3 hours.

Expert-written essays crafted with your exact needs in mind

Turttiopsis Dohrnii and The Idea of Immortality

Seattle aquarium featured advantage, the great white shark: ruthless predator of the ocean, a study on the purpose of marine biology and the effect of the ocean phenomena on aquatic animals, understanding the detrimental effects of harmful algae in the scientific study of marine life, marine ecology, a study of the flourishing aquatic life at the monterey bay marine sanctuary, suitable course for marine engineering course, blue economy: sustainable usage of marine resources, marine ornamental sector in sri lanka, malaysian aquaculture sector: analysis of current issues, seaweed aquaculture methods and strategies for cultivation, analysis of marine invasive species and their impact on biodiversity, addressing the urgent issue of ocean acidification, tackling a global crisis: marine plastic pollution, ocean acidification: the silent threat to marine ecosystems, understanding and preserving bioluminescence in puerto rico and florida, narwhal life cycle, relevant topics.

• Biodiversity
• Water Cycle

By clicking “Check Writers’ Offers”, you agree to our terms of service and privacy policy . We’ll occasionally send you promo and account related email

No need to pay just yet!

We use cookies to personalyze your web-site experience. By continuing we’ll assume you board with our cookie policy .

• Instructions Followed To The Letter
• Deadlines Met At Every Stage
• Unique And Plagiarism Free

Talk to our experts

1800-120-456-456

Marine Biology

Introduction.

Marine Biology is the study of marine, also called otherwise as aquatic animals, about their life cycle, activities, different facts related to the marine aquatic ecosystem along with its habitats, and their interactions with the environment. It is said that in biology, many families, genera, phyla have a few species living in the sea, and others living on land and marine biology classifies species depending on the environment rather than based on taxonomy.

[Image will be uploaded soon]

Charles Darwin is suitably the best known for his evolution theory, and James Cook is best known as the father of marine biology or modern marine biology. He also performed several significant research to advance the study of marine biology during the 18th Century, which encouraged other scientists also in their inventions.

What is Marine Biology?

Marine biology is the marine ecosystem's scientific study, including various types of tidal zones, saltwater swamps, oceans, mangroves, rivers, streams, and so on along with their features, depth of the ocean beds, various types of marine life, which primarily involves a vast number of species, from the zooplankton and microscopic phytoplankton to massive organisms such as aquatic plants, various types of fish, sharks, and whales that survives, lives, and exists, under the surface of the ocean. Overall, in addition, Marine biology also includes the study of the inter-relationship between ecology, environment, and marine life.

The study of Marine biology explains a wide range of adaptations that involve the physiological, structural, life cycle, and behavioural adaptations of marine habitats. The taxonomy records say that marine habitats are older than terrestrial habitats, as life originated in the oceans was around 3.1 billion to 3.4 billion years ago.

Why is Marine Biology Important?

As the growing global population agitating our society's ability to produce food, water, shelter, and we will continue to look at the oceans to help sustain our basic needs.

Technology advances, added with demand, will improve our ability to derive food, energy sources, drinking water, transportation, and waste disposal from the ocean.

It will be up to the present and future generations to build upon our existing ocean knowledge and its potential to help meet the world's needs and its inhabitants.

Marine Biology vs. Biological Oceanography

The difference between these two terms, "marine biology" and "biological oceanography" is subtle, and are often used interchangeably. Marine biology is the marine species' study that lives in saltwater environments and in oceans. Biological oceanography also studies marine species, but only in the oceanography context. So a marine biologist might study the reproductive behavior of anchovies, where biological oceanographers might study the impact of cold upwellings on anchovy populations off the coast of South America.

Marine Life

Microscopic Life

Inhabitants, as the largest environment on Earth, marine microbial systems drive changes in every global system. Microbes are primarily responsible for all the photosynthesis that virtually occurs in the ocean, and the cycling of carbon, phosphorus, nitrogen, and many other nutrients and trace elements as well.

Incredibly the microscopic life undersea is diverse and still understood poorly. For suppose, the virus's role in the marine ecosystems is being explored barely even at the beginning of the 21st Century.

The phytoplankton role is understood better due to its critical position as the most numerous primary producers on Earth. Phytoplankton is divided into cyanobacteria (also known as blue-green bacteria/algae), different types of algae (red, brown, yellow-green, and green), diatoms, euglenoids, dinoflagellates, coccolithophorids, cryptomonads, chlorophytes, chrysophytes, silicoflagellates, and prasinophytes.

Plants and Algae

Microscopic algae and plants give important habitats for life and sometimes act as a hiding place for invertebrates for larval forms of larger fish and foraging places.

Algal life is very diverse and widespread under the ocean. Microscopic photosynthetic algae contribute a bigger proportion of the world's photosynthetic output compared to all the combined terrestrial forests. Actually, most of the niche occupied by sub plants on land is occupied by macroscopic algae in the ocean, like Sargassum and kelp, which are usually known as seaweeds, which create kelp forests.

Plants surviving in the sea are often found in shallow waters, like the seagrasses (examples of which are Zostera, eelgrass, and Thalassia, turtle grass). These plants have adapted to the high range of salinity of the environment of the ocean. Also, the intertidal zone is a good place to find plant life in the sea, where cordgrass or mangroves or beach grass might grow.

Invertebrates

Invertebrates make up a considerable portion of all life in the sea as on land. Invertebrate sea life involving Cnidaria like the sea anemones, jellyfishes; sea worms including Nemertea, Echiura, phyla Platyhelminthes, Sipuncula, Phoronida, and Chaetognatha; Mollusca including shellfish, squid; Ctenophora; Arthropoda including Crustacea and Chelicerata; Bryozoa; Porifera; Echinodermata including starfish; and Urochordata including tunicates or sea squirts. The invertebrates have no backbone, and there are over a million species count.

FAQs on Marine Biology

1. Explain the Marine Habitats?

Ans. Marine habitats can be further divided into:

Coastal Habitats

Open Ocean habitats

Coastal habitats are found in the extended area from the shoreline to the edge of the continental shelf. Most marine life is appeared to found in coastal habitats, even though the shelf area occupies only 7% of the total ocean area.

Whereas the Open ocean habitats are happened to found in the deep ocean, beyond the edge of the continental shelf. Marine habitats alternatively can be divided into demersal and pelagic habitats. Demersal habitats stay near or on the bottom while the Pelagic habitats are found in the open water column or near the surface, away from the bottom of the ocean, and affected by ocean currents.

2. Mention a few differences between Marine Biology and Marine Science?

Ans. Marine Biology is importantly a subdiscipline of Marine Science. Marine Biology covers mostly living organisms, and they are found generally in marine systems. It does not fully address the physical and chemical aspects of the oceans, like climate, currents, tidal effects, wave action, and so on, except in relation to how these things affect the biological organisms directly. Marine Science essentially covers everything from marine biology, marine chemistry, marine ecology, marine geology, and more related fields. Marine Science is a much-encompassing field, and also Marine Science is more marketable.

Biology • Class 12

ENCYCLOPEDIC ENTRY

Marine pollution.

Marine pollution is a combination of chemicals and trash, most of which comes from land sources and is washed or blown into the ocean. This pollution results in damage to the environment, to the health of all organisms, and to economic structures worldwide.

Biology, Ecology, Earth Science, Oceanography

Loading ...

Learning materials

Instructional links.

• Marine Pollution (Google Doc)

Marine pollution is a growing problem in today’s world. Our ocean is being flooded with two main types of pollution: chemicals and trash.

Chemical contamination, or nutrient pollution, is concerning for health, environmental, and economic reasons. This type of pollution occurs when human activities, notably the use of fertilizer on farms, lead to the runoff of chemicals into waterways that ultimately flow into the ocean. The increased concentration of chemicals, such as nitrogen and phosphorus, in the coastal ocean promotes the growth of algal blooms , which can be toxic to wildlife and harmful to humans. The negative effects on health and the environment caused by algal blooms hurt local fishing and tourism industries.

Marine trash encompasses all manufactured products—most of them plastic —that end up in the ocean. Littering, storm winds, and poor waste management all contribute to the accumulation of this debris , 80 percent of which comes from sources on land. Common types of marine debris include various plastic items like shopping bags and beverage bottles, along with cigarette butts, bottle caps, food wrappers, and fishing gear. Plastic waste is particularly problematic as a pollutant because it is so long-lasting. Plastic items can take hundreds of years to decompose.

This trash poses dangers to both humans and animals. Fish become tangled and injured in the debris , and some animals mistake items like plastic bags for food and eat them. Small organisms feed on tiny bits of broken-down plastic , called micro plastic , and absorb the chemicals from the plastic into their tissues. Micro plastics are less than five millimeters (0.2 inches) in diameter and have been detected in a range of marine species, including plankton and whales. When small organisms that consume micro plastics are eaten by larger animals, the toxic chemicals then become part of their tissues. In this way, the micro plastic pollution migrates up the food chain , eventually becoming part of the food that humans eat.

Solutions for marine pollution include prevention and cleanup. Disposable and single-use plastic is abundantly used in today’s society, from shopping bags to shipping packaging to plastic bottles. Changing society’s approach to plastic use will be a long and economically challenging process. Cleanup, in contrast, may be impossible for some items. Many types of debris (including some plastics ) do not float, so they are lost deep in the ocean. Plastics that do float tend to collect in large “patches” in ocean gyres. The Pacific Garbage Patch is one example of such a collection, with plastics and micro plastics floating on and below the surface of swirling ocean currents between California and Hawaii in an area of about 1.6 million square kilometers (617,763 square miles), although its size is not fixed. These patches are less like islands of trash and, as the National Oceanic and Atmospheric Administration says, more like flecks of micro plastic pepper swirling around an ocean soup. Even some promising solutions are inadequate for combating marine pollution. So-called “ biodegradable ” plastics often break down only at temperatures higher than will ever be reached in the ocean.

Nonetheless, many countries are taking action. According to a 2018 report from the United Nations, more than sixty countries have enacted regulations to limit or ban the use of disposable plastic items. The National Geographic Society is making this content available under a Creative Commons CC-BY-NC-SA license . The License excludes the National Geographic Logo (meaning the words National Geographic + the Yellow Border Logo) and any images that are included as part of each content piece. For clarity the Logo and images may not be removed, altered, or changed in any way.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Production Managers

Program specialists, last updated.

February 22, 2024

User Permissions

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text on this page is printable and can be used according to our Terms of Service .

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

Related Resources

Why is marine life important and how can it be protected?

Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Writing9 with appropriate and specific direction to the original content.

Fully explain your ideas

To get an excellent score in the IELTS Task 2 writing section, one of the easiest and most effective tips is structuring your writing in the most solid format. A great argument essay structure may be divided to four paragraphs, in which comprises of four sentences (excluding the conclusion paragraph, which comprises of three sentences).

For we to consider an essay structure a great one, it should be looking like this:

• Paragraph 1 - Introduction
• Sentence 1 - Background statement
• Sentence 2 - Detailed background statement
• Sentence 3 - Thesis
• Sentence 4 - Outline sentence
• Paragraph 2 - First supporting paragraph
• Sentence 1 - Topic sentence
• Sentence 2 - Example
• Sentence 3 - Discussion
• Sentence 4 - Conclusion
• Paragraph 3 - Second supporting paragraph
• Paragraph 4 - Conclusion
• Sentence 1 - Summary
• Sentence 2 - Restatement of thesis
• Sentence 3 - Prediction or recommendation

Our recommended essay structure above comprises of fifteen (15) sentences, which will make your essay approximately 250 to 275 words.

Discover more tips in The Ultimate Guide to Get a Target Band Score of 7+ » — a book that's free for 🚀 Premium users.

• Check your IELTS essay »
• Find essays with the same topic
• View collections of IELTS Writing Samples
• Show IELTS Writing Task 2 Topics

Some people think that the best way to succeed in life is to get a university education, while others disagree and say that it is no longer true nowadays. Discuss both views and give your own opinions.

You went to another city for a training course and stayed at a friend’s house for a week. they have been great hosts. write a letter to your friend. in your letter, thank them for having you at their house for a week express your gratitude for their hospitality say how much you miss them, many people go through life doing work that they hate or have no talent for. why does this happen what are the consequences of this situation, some people believe that it is best to accept a bad situation, such as an unsatisfactory job or shortage of money. others argue that it is better to try and improve such situations. discuss both these views and give your own opinion., some people think that tourists should follow the traditional customs of the host country. do you agree or disagree.

We use cookies to enhance our website for you. Proceed if you agree to this policy or learn more about it.

• Essay Database >
• Essays Samples >
• Essay Types >
• Argumentative Essay Example

Marine Life Argumentative Essays Samples For Students

6 samples of this type

While studying in college, you will inevitably need to compose a bunch of Argumentative Essays on Marine Life. Lucky you if linking words together and organizing them into meaningful text comes easy to you; if it's not the case, you can save the day by finding an already written Marine Life Argumentative Essay example and using it as a template to follow.

This is when you will definitely find WowEssays' free samples catalog extremely useful as it embodies numerous expertly written works on most various Marine Life Argumentative Essays topics. Ideally, you should be able to find a piece that meets your criteria and use it as a template to develop your own Argumentative Essay. Alternatively, our skilled essay writers can deliver you a unique Marine Life Argumentative Essay model crafted from scratch according to your personal instructions.

Example Of Argumentative Essay On Littering

Free senegal: marine pollution argumentative essay example, introduction, argumentative essay on shutdown of seaworld.

Don't waste your time searching for a sample.

Get your argumentative essay done by professional writers!

Just from $10/page

Effects Of Public Smoking Argumentative Essay

Oceanic acidification argumentative essay examples, oil drilling and its effects on the world argumentative essay.

Password recovery email has been sent to [email protected]

Use your new password to log in

You are not register!

By clicking Register, you agree to our Terms of Service and that you have read our Privacy Policy .

Now you can download documents directly to your device!

Check your email! An email with your password has already been sent to you! Now you can download documents directly to your device.

or Use the QR code to Save this Paper to Your Phone

The sample is NOT original!

Short on a deadline?

Don't waste time. Get help with 11% off using code - GETWOWED

No, thanks! I'm fine with missing my deadline

• Apply to UMaine

UMaine News

New book details UMaine’s journey of ‘Becoming Modern’ 

The University of Maine marked its 100th anniversary in 1965, prompting widespread celebration and discussions of its future.

University leaders, community members, policymakers and other supporters devised plans to bolster enrollment, programs, research and public service. Yet the transformative growth UMaine experienced in the five decades between its centennial year and 2015 surpassed these visions, according to a new book published by University of Maine Press.

“Becoming Modern: The University of Maine, 1965–2015” features 33 essays that depict UMaine’s transition from a traditional land grant university — one primarily focused on agriculture, business and engineering — to “a vastly more diversified institution with a national and international reputation in many fields.” 

“As the University of Maine’s academic offerings, research and scholarship enterprise, and engagement continue to evolve, having read about one of the most transformative periods of its history has been enriching and inspiring,” said UMaine President Joan Ferrini-Mundy. “I commend the editors for creating such a compelling book filled with in-depth information and diverse perspectives on our modernization. I am confident it will captivate any reader and inspire the higher education leaders of tomorrow.” 

Readers will learn about the foundation and expansion of scholarship, research and service in a variety of fields during the late 20th century, including marine science, climate change, public policy, renewable energy and the performing arts. 

They also will explore the vast changes in athletics, Fogler Library, relations with the town of Orono, and graduate and honors education. Additionally, a few essays in the book discuss expanding opportunities for women and Indigenous scholars at UMaine at a time of growing social change nationwide. 

“I think people will learn a lot from the book and will have a new appreciation for the University of Maine,” said Betsy Rose, publications specialist with the University of Maine Press, a division of Fogler Library. “I was especially intrigued by how things changed for women between 1965 and the present, how the Climate Change Institute evolved, and how hard faculty worked to get support from the state legislature in the 1990s.”

The late Howard Segal, editor of the book and former UMaine history professor, began working on the book in 2012. He solicited essays from 46 contributors — faculty, staff and students from varying disciplines — and wrote the introductory and concluding chapters. 

In addition to showcasing UMaine’s historic milestones following its centennial, Segal described forecasts from 1965 about how UMaine would evolve. In “Back to the Future: An Introduction,” the book’s first essay, Segal wrote that these predictions show “what those visions reveal about the persons, movements, organizations and culture that project them.” 

After Segal’s death in 2020, his wife, Deborah Rogers, associate editor and UMaine English professor, and co-editor Ann Acheson completed the book, which retiring University of Maine Press Director, Michael Alpert, designed and typeset. 

“As a historian of American technology and utopianism, Howard worked for the perfectibility of institutions, government, society and culture,” said Rogers. “He wanted to create this book as a contribution to land grant history and the history of a university that was dear to his heart. It’s bittersweet that Howard didn’t live to see its completion, but I know it would have given him enormous satisfaction and pride, as it does to all of us who collaborated on this project.”

Since the University of Maine was one of the first land-grant universities, Segal wanted to examine its importance in the evolution of these institutions, which were established nationally by the Morrill Land Grant Act of 1862. In the prefix, he wrote, “All articles in the book aim to provide a delicate balance between a coffee table book and a serious scholarly work. I hope this volume can contribute not only to land-grant historiography but also to the history of ‘the college of our hearts always.’”

“Dr. Segal’s labor of love, which picks up where ‘The First Century: A History of the University of Maine, 1865–1965’ left off, is a great contribution to the UMaine Press publications, which include such important regional works as “A Passamaquoddy – Maliseet Dictionary: Peskotomuhkati Wolastoqewi Latuwewakon” and the award-winning Historical Atlas of Maine,” said Daisy Singh, dean of libraries at UMaine. “It is also a crowning achievement for retiring Director Michael Alpert who, along with Associate Provost for Academic Affairs and Faculty Development and Acting Press Director Gabe Paquette, have begun a strategic planning process which will usher in a period of increased visibility and digital access to UMaine Press publications.”  

The book is available for purchase online and at the University Bookstore. 

Contact: Marcus Wolf, 207.581.3721; [email protected]

• UMaine Today Magazine
• Submit news