Marine Habitat Facts

Sound

Oceans cover approximately 70% of the earth’s surface with an average depth of 2.4 miles, or 3,800 meters. The marine ecosystem, in addition to the temperate and tropical oceans, includes the shorelines, with mud flats, rocky and sandy shores, tidepools, barrier islands, estuaries, salt marshes, and mangrove forests making up the shoreline segment. Marine ecosystems support a great diversity of life and variety of habitats. The ocean is a major influence on weather and climate.

Location

Conventionally, the ocean has been divided into four major ocean basins: Atlantic, Pacific, Indian and Arctic oceans. Specific marine ecosystems such as coral reefs, estuaries, salt mashes, mangrove forests are found throughout the world, but are characteristic of certain areas, depending on climate, geography, water temperature, and other physical factors.

Visit our coral reef fact sheet for more information on these amazing and imperiled habitats >>

Plants

Marine habitats are the home to seaweeds, or marine algae (brown, green, red), sea grasses, which are the only marine flowering plants, and mangroves, located on muddy tropical shores.

Animals

Marine ecosystems are homes to protozoans, marine invertebrates (echinoderms, mollusks, segmented and non-segmented worms, jellies, coral, sea anemones, hyroids) marine vertebrates (fishes, birds, mammals), and plankton (phyto and zooplankton).

Climate

Did You Know?

The average temperature of the oceans is about 39ºF, or 2ºC.

Monsoon, tropical, subtropical, temperate, polar, subpolar.

Threats

Marine ecosystems are under a variety of threats, including offshore oil drilling, oil spills, pollutions, marine debris, overfishing, habitat destruction and climate change.

Learn more about Defenders' work to protect numerous marine species from overexploitationn >>

Legal Status/Protection

Less than one percent of marine habitats are protected - compared with 11.5 percent of global land area. A variety of laws and regulations exist to protect marine life and habitats. Some of these protections include marine reserve, marine protected areas, and national marine sanctuary designations. Additional laws, treaties, and protections include the United Nations Law of the Sea, Marine Mammal Protection Act, Endangered Species Act, Magnuson-Stevens Fishery Conservation and Management Act, International Migratory Bird Act, and others.

How You Can Help

Help preserve marine habitat and wildlife by adopting an animal at our Wildlife Adoption & Gift Center.
Take action for wildlife at our Wildlife Action Center.