The aquatic biome includes habitats around the world dominated by water. Aquatic ecosystems are divided into two main groups based on their salinity—freshwater habitats and marine habitats.

●  Freshwater habitats are aquatic habitats with low levels of salt, less than one percent.  They include rivers, lakes, streams, ponds, swamps, wetlands, bogs and lagoons.

●  Marine habitats are aquatic habitats with salt concentrations of more than one percent. They include oceans, seas and coral reefs.

Some habitats exist where saltwater and freshwater mix together. These include mud flats, mangroves and salt marshes. Aquatic ecosystems support a diverse assortment of animals including fishes, amphibians, reptiles, mammals, birds and invertebrates.



When evaporated sea water falls as rain, it flows down mountain streams creating rivers and lakes. Rain water feeds freshwater rivers, which then flows back into the sea. Streams, rivers and lakes are home to countless animal species.

The two main types of freshwater habitat are rivers and lakes. Lakes are often fed by streams or rivers. They can also be enclosed areas where species live that are found nowhere else on the planet. Rivers usually contain large animals able to cope with strong currents, as well as animals such as crabs and birds that feed on the fish within the water.

Freshwater rivers provide habitat to a wide variety of species including fish, amphibians, reptiles, insects, birds and mammals. An extraordinary number of fish species inhabit streams and rivers.

Freshwater lakes are also home to a vast variety of wildlife. Some species spend their entire lives in one area. Others visit momentarily to eat and drink. Many species are specially adapted to life in particular lakes. Large mammals, including zebras, primates, giraffes and deer, visit lakes to drink.

Many freshwater habitats have been drastically affected by human activities. Chemicals and pesticides contaminate the water, as well as waste water. Animals and plants that inhabit the water can be affected, as are the animals that eat them.


Oceans create the largest habitat in the world. Countless animal species inhabit the planet's oceans which cover over 75% of the earth.

The two main types of ocean habitat are coastal, inshore habitats found around land, and open ocean habitats that stretch around the planet. More animal species live in the rich, shallower waters than the deep sea, though animals live throughout the oceans.

The ocean landscape is as vast and varied as on land, featuring underwater continental shelves, mountains, valleys, volcanoes, trenches and plains.

Warmer, coastal waters around the globe are home to the majority of species. These areas feature more food sources than the deep ocean. Smaller aquatic animals often inhabit the shallower regions. Coastal waters provide them with a variety of places to hide, with fewer large predators. Larger animals tend to prefer deeper regions beneath the waves along the continental shelves.

Plankton -- microscopic plants and animals, fish eggs and animals in their larvae form -- provide a plentiful food source for many marine animals. Tiny fishes and crustaceans, to the largest animal on the planet, the blue whale, feed on this vital food source.

The two largest threats to ocean habitats are over-fishing and pollution. Pollution from the land and air accumulate in the sea with devastating effects to many plant and animal species. Over-fishing threatens many species with extinction.


Coral reefs are the richest habitats on the earth. Found along the coastlines, they provide habitat to countless plant and animal species including fish, reptiles, invertebrates, echinoderms and crustaceans. Coral reefs are located in the tropical and sub-tropical coastal regions where it is always warm, day and night, year-round.

The two main types of coral reef habitats are soft coral reefs and hard coral reefs. Soft corals are animals that move through the water, eventually settling. Hard corals are the reef-building corals that are hard coral shells left behind when corals die.

The largest coral reefs are located along the south-west coast of Africa, in the Caribbean and all around Australia, south-east Asia and the coastal regions of the South Pacific Ocean.

So rich in life and biodiversity, coral reefs are home to an incredible variety animal species able to survive together with little competition for food. Animal species that inhabit coral reefs vary tremendously in shape, size and color. Sea urchins, starfish and crustaceans are invertebrates that call coral reefs home. Sea snakes hunt small fish and eels in the coral reefs. Eels and seahorses are among the many fish species. Sharks do not live permanently in coral reefs, but visit often in search of prey. Sea turtles also make frequent trips to coral reefs in search of food.

The threats to coral reefs and coastline wildlife include commercial fishing, pollution and storms. Dredging involves dragging fishing nets across the sea bed, destroying coral reefs in the process. Many animal species that inhabit coral reefs are on the brink of extinction. Sea storms, such as tsunamis, can also reek havoc on coral reef environments.



Wetlands are found throughout the world, often in more temperate regions where vegetation grows quickly. These large areas of water contain a wealth of plants and are broken up by small islands of land. Wetlands include swamps, marshes, fens and bogs. Many wildlife species are specifically adapted to wetland environments, including fish, amphibians, birds, mammals, reptiles and insects.

The two main types of shallow watery areas are swamps and wetlands. Swamps are usually located in forested areas. Trees, such as mangrove trees, survive in salt-water conditions and require ample space for their roots. Wetlands are usually near large rivers or estuaries that flood when river banks burst from a lot of rain.

Mangrove swamps are one of the richest habitats on the planet. Numerous animals species live above and below the water's surface. Many animal species that live in mangrove forests are found nowhere else on earth. The mangrove tree's enormous roots provide shelter to small fishes, amphibians and reptiles and provide a way for the animals to get in and out of the water. Larger animals have ample fish to feed on.

Large aquatic birds such as heron spear fish with long beaks in wetland habitats. Salt-water swamps contain snapping turtles, crabs, crocodiles and alligators. Amphibians and reptiles inhabit the water's edge. Many insects live, and lay their eggs, in wetland habitats...providing food for frogs and lizards.

The main threats to wetlands are deforestation and pollution. The animals in wetland habitats are specifically adapted to their environment and are vulnerable to toxins in the water and air.



Islands form when land breaks away from large land masses or volcanoes erupt on the sea floor. They are found throughout the world. Their isolated nature results in unique wildlife species, often different from their counterparts living in mainland habitats. Some island animal species have developed completely separately from mainland species.

Numerous habitats including forests, wetlands, deserts and tundra can be found on different islands. Limited in size and resources, ecosystems on islands are fragile and easily disturbed. Human activity and the introduction of new species on islands has caused much harm, making many species endangered or extinct. With nowhere else for them to go, the loss of habitat or food sources is particularly damaging to island animals.

Lemurs live only on the island of Madagascar, the tree kangaroo only in Papua New Guinea, the kiwi only in New Zealand and the orangutan only on the Indonesian islands of Borneo and Sumatra. Separated from the mainland, these species have adapted to their isolated environments. The kiwi and the kakapo birds have adapted to a flightless lifestyle since there were no large predators on the islands to flee from. The introduction of predators by humans threatens their survival. Orangutans suffer from mass deforestation in south-east Asia and the exotic pet trade.

A breaking point has been reached in conserving the fragile habitats of islands. Without immediate action to save these precious ecosystems, many species will be lost forever.




You can make a big difference for ocean conservation and species preservation. There are many easy lifestyle changes that can aid in the effort of saving our oceans and the animals that inhabit them. Sound ocean policy depends on the election of proper public officials. Do your homework and decide wisely before casting your vote. Don’t forfeit your right to vote; on the contrary, remain politically active even after Election Day. Contact your representative and voice your questions and concerns. Be active.


We live on land, but our world is a water world. The ocean covers 70% of Earth's surface. The average depth of the ocean is about 2.7 miles. In some places, the ocean is deeper than the tallest mountains are high. The ocean contains about 97% of all the water on Earth. The ocean plays a starring role in whatever happens with the environment. One big part of its role is to soak up energy (heat) and distribute it more evenly around the Earth. Another part is to soak up CO2.


Water could be the key to finding life. There aren’t many qualities that are true of all life on Earth, but the need for water is one of them. It’s in all living things, whether they live at the bottom of the ocean or the driest desert. Water made life possible on Earth. Because of this, astrobiologists (scientists who search for life on other planets) think our best bet for finding life is to search for water. Almost all Earth’s water is in the oceans. A whopping 96.5 percent of water on Earth is in our oceans, covering 71 percent of the surface of our planet.


Ocean acidification refers to a reduction in the pH of the ocean over an extended period time, caused primarily by uptake of carbon dioxide (CO2) from the atmosphere. For more than 200 years, or since the industrial revolution, the concentration of carbon dioxide (CO2) in the atmosphere has increased due to the burning of fossil fuels and land use change. The ocean absorbs about 30 percent of the CO2 that is released in the atmosphere.


"Dead zone" is a more common term for hypoxia, which refers to a reduced level of oxygen in the water. Hypoxic zones are areas in the ocean of such low oxygen concentration that animal life suffocates and dies, and as a result are sometimes called "dead zones." One of the largest dead zones forms in the Gulf of Mexico every spring.


In general, oil spills can affect animals and plants in two ways: from the oil itself and from the response or cleanup operations. Understanding both types of impacts can help spill responders minimize overall impacts to ecological communities and help them to recover much more quickly. Spilled oil can harm living things because its chemical constituents are poisonous.


Our oceans are filled with items that do not belong there. Huge amounts of consumer plastics, metals, rubber, paper, textiles, derelict fishing gear, vessels, and other lost or discarded items enter the marine environment every day, making marine debris one of the most widespread pollution problems facing the world's oceans and waterways.


The image of seals and sea lions conjures up thousands of these creatures basking on the rocky beaches of the U.S. West coast, Australia and Tasmania and ice floes of the Arctics. While similarities between these two amphibious mammals seem apparent, there are some inherent differences. The pinniped, the family to which these two belong, consists of the phocidae or true seals and otariidae or sea lions. True seals are believed to have descended from a terrestrial creature closely resembling the weasel, while the sea lion traces back its origins to a bear-like animal.


The dolphin is found in almost all seas and oceans of the world, and even some rivers. Their amazing intelligence, creativity, playfulness and complex culture captures the hearts and minds of humans around the globe. But these fascinating creatures are continuously under threat from human activities, including marine pollution, habitat degradation, hunting, low frequency sonar and fishing gear. Many dolphin species face an uncertain future.


Numerous natural impacts, as well as human activities, affect kelp forest environments. The factors influencing kelp forest stability are diverse: kelp harvesting; grazing by fishes, sea urchins, and crustaceans; plant competition; storms; El Niño events; sedimentation; and pollution. By most accounts, because of its spectacular growth rates, kelp recovers quickly from physical disturbances such as storms that might uproot the fragile plants.


In nature, all living things are in some way connected. Within each community each species depends on one or more of the others for survival. And at the core of individual ecosystems is a creature, or in some cases a plant, known as a keystone species. This species operates much like a true key stone, which is the stone at the top of an arch that supports the other stones and keeps the whole arch from falling down.


Kelp forests grow predominantly on the Pacific Coast, from Alaska and Canada to the waters of Baja California. Tiered like a terrestrial rainforest with a canopy and several layers below, the kelp forests of the eastern Pacific coast are dominated by two canopy-forming, brown macroalgae species, giant kelp (Macrocystis pyrifera) and bull kelp (Nereocystis leutkeana).


Mangrove forests are made up of trees that live along tropical and subtropical intertidal shorelines. The trees are easily recognizable by their dense mats of thick, stick-like roots that rise out of the mud and water. These roots (called “prop roots”) slow the movement of water as the tides flow in and out, allowing sediments to settle onto the muddy bottom.


A wetland is an area of land that is saturated with water. There are many different kinds of wetlands and many ways to categorize them. Wetlands generally fall into five general types: marine (ocean), estuarine (estuary), riverine (river), lacustrine (lake), and palustrine (marsh). Common names for wetlands include marshes, estuaries, mangroves, mudflats, mires, ponds, fens, swamps, deltas, coral reefs, billabongs, lagoons, shallow seas, bogs, lakes, and floodplains, to name just a few!


Coral reef ecosystems are complex, dynamic, and sensitive systems. Although they are geologically robust and have persisted through major climactic shifts, they are however, sensitive to small environmental perturbations over the short-term. Slight changes in one component of the ecosystem affect the health of other components. Changes may be attributed to a number of causes but generally fall into two categories, natural disturbances and anthropogenic disturbances.


Hidden beneath the ocean waters, coral reefs teem with life. Coral reefs support more species than any other marine environment and rival rainforests in their biodiversity. Countless numbers of creatures rely on coral reefs for their survival. Corals are animals, even though they may exhibit some of the characteristics of plants and are often mistaken for rocks. In scientific classification, corals fall under the phylum Cnidaria and the class Anthozoa.


Corals are popular as souvenirs, for home decor and in costume jewelry, yet corals are living animals that eat, grow, and reproduce. It takes corals decades or longer to create reef structures, so leave corals and other marine life on the reef. Corals have long been popular as souvenirs, for home decor, and in jewelry, but many consumers are unaware that these beautiful structures are made by living creatures.


Try this: Taste plain water. Then taste sparkling water (carbonated water), with no flavoring. Besides the slight tickle or sting of the bubbles in the sparkling water, do you notice anything else? The sparkling water tastes just a little bit sour. The more bubbles, the more sour the water. The reason is that adding carbon dioxide to water is like adding a few drops of lemon juice. It makes the water a little acidic.


There is strong evidence that global sea level is now rising at an increased rate and will continue to rise during this century. A warming climate can cause seawater to expand and ice over land to melt, both of which can cause a rise in sea level. While studies show that sea levels changed little from AD 0 until 1900, sea levels began to climb in the 20th century.


Penguins waddle around in ungainly fashion on ground, but once in water they transform into expert swimmers and can cruise at speeds of 15 miles per hour. Although the penguin is a bird species, they are unable to fly because they have flippers instead of wings. The penguin's black body and white belly is an excellent aquatic camouflage when it sets out to hunt for food, which mainly consists of fish, crabs, squid and shrimps.


More than half the world’s sea turtles have ingested plastic or other human rubbish. Recent research indicates that approximately 52 percent of turtles world-wide have eaten debris. Threats to marine turtle species come from an estimated four million to 12 million tons of plastic which enter the oceans annually. Plastic ingestion can kill turtles by blocking the gut or piercing the gut wall, and can cause other problems through the release of toxic chemicals into the animals’ tissues.


Rivers are essential to the health of the Earth. They are among the most diverse ecosystems on the planet. Rivers can be degraded by many human activities, including pollution, channelization and watershed destruction – but dams have the greatest impacts. Dams are barriers that hold back water and raise the water level, resulting in a reservoir. They are constructed for electric production, flood control, water supply and irrigation. Despite their benefits to humans, dams are destroying riparian ecosystems.


Viewing and interacting with marine mammals in the wild attracts sufficient numbers of people. A small industry has grown from it. Well intentioned or not, this industry and the public it serves frequently do not take into account the well-being of the animals they view. Marine mammal specialists and advocates have sufficient cause to be concerned. Marine mammals in their natural habitat attract many tourists. Anyone who approaches a wild animal to touch, feed, or pose for photographs with it may be guilty of unintentional harassment. 


Marine conservation, also known as marine resources conservation, is the protection and preservation of ecosystems in oceans and seas. Marine conservation focuses on limiting human-caused damage to marine ecosystems, and on restoring damaged marine ecosystems. Marine conservation also focuses on preserving vulnerable marine species. Marine conservation is the study of conserving physical and biological marine resources and ecosystem functions. This is a relatively new discipline. Marine conservationists rely on a combination of scientific principles derived from marine biology, oceanography and fisheries science, as well as on human factors.


Wetland conservation is aimed at protecting and preserving areas where water exists at or near the earth's surface, such as swamps, marshes and bogs. Wetlands cover at least 6% of the earth and have become a focal issue for conservation due to the 'ecosystem services' they provide. More than three billion people, around half the world’s population, obtain their basic water needs from inland freshwater wetlands. The same number of people rely on rice as their staple food, a crop grown largely in natural and artificial wetlands. In some parts of the world, such as the Kilombero wetland in Tanzania, almost the entire local population relies on wetland cultivation for their livelihoods.


Coral reefs, rainforest of the sea, are one of nature's most remarkable creations - teaming with thousands of unique and valuable plants and animals. More than one-quarter of all marine species depend on coral reefs for their survival. Humans depend on the survival of coral reefs too. Coral reefs provide a natural wave barrier which protects beaches and coastlines from storms and floods. Coral reefs have existed on our planet for over 50 million years, but recently we have lost over 20% of the world's reefs in just the last 20 years. Up to 70% of the reefs may be destroyed by humans in the next few decades if we don't take immediate action.


Dolphins are often regarded as one of earth's most intelligent animals. They are social, living in pods of up to a dozen individuals. In places with a high abundance of food, pods can merge temporarily, forming a superpod; such groupings may exceed 1,000 dolphins. Individuals communicate using a variety of clicks, whistles and other vocalizations. They make ultrasonic sounds for echolocation. Membership in pods is not rigid; interchange is common. However, dolphins can establish strong social bonds.


Each year thousands of seals are killed in Canada. The seals suffer painful and lingering deaths. The weapon used is a club, the brutal hakapik. Sometimes the seals are skinned alive. Sealers often use sharpened steel hooks to drag the creatures on board their vessels. Seal-clubbing is justified by the Canadian government because its victims are adversely affecting the profits of the Newfoundland fishing industry.


The majority of the world's fisheries are in a state of collapse. Too many boats are chasing too few fish. Many of the fish species currently in decline serve as important food sources for sea animals who, unlike humans, have no other food choices. In the Bering Sea, the effects of overfishing on marine animals are obvious. Fur-seal populations have not increased despite a long-standing ban on commercial hunting.


Don't be afraid OF sharks; be afraid FOR them. There are more misunderstandings and untruths about sharks than almost any other group of animals on the planet. While many people fear sharks, it is the sharks who should be fearing us. According to the shark attack file, maintained by the Florida Museum of Natural History, on average 5 people die worldwide from shark attacks. Research published in 2006 found that up to 70 million sharks are killed by humans each year, mostly for their fins.


While some claim the manatee is ugly, with ‘a face only a mother could love,’ most people seem drawn to this fascinating marine creature. Whether it’s their sad, puppy-like demeanor, or their sluggish, gentle manner, something about manatees is awfully endearing. The manatee, or sea cow, is an aquatic mammal. With a round cylindrical body, they can measure from 8 to 13 feet from tail to head. Weights can vary from 450 lbs for the smallest species to 1,300 lbs for the larger ones.


Whales are among the most fascinating and talked about creatures on the planet. These mammals are not just the largest creatures of the ocean, but of the Earth. Even the smallest species, the dwarf sperm whale, is 8.5 feet long and can weigh at least 135 kilograms. The biggest, the blue whale, is over a 100 feet in length and can weigh as much as 210 tons. Whale species include the killer whale, blue whale, humpback whale, the narwhal or narwhale, beluga whale, gray whale, bowhead whale, fin whale, North Atlantic right whale and dozens more.