marine ecosystem

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References & Edit History Quick Facts & Related Topics

Images & Videos

generalized aquatic food web

hydrothermal mussels

palinurid lobster life cycle

Algae, primarily diatoms, dinoflagellates, and coccolithophorids, which are often collectively called phytoplankton, are the base of the food chain for all marine organisms.

Upwelling process along coast

marine food chain

Learn about microplastic and its harmful effect on marine animals

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Star fish entangled in gillnet

Talking Ocean Trash: Ghost Gear Keeps on Fishing

A large school of mano (sharks) called Galapagos sharks at Maro Reef in the Papahanaumokuakea Marine National Monument. Galapagos shark (Carcharhinus galapagensis)a worldwide species of requiem shark, family Carcharhinidae.

Saving Sharks in the 2020s

Great Barrier Reef coral bleached area map and infographic

Coral Bleaching: A Threat to Our Reefs

algae. Lake Erie. Dead fish in harmful algal bloom along the southeast Lake Erie shore of Pelee Island, Ontario, Canada, 5 miles north of the international line Aug. 19, 2011. Toxic algae blooms, drinking water, 4th largest of 5 Great Lakes

Harmful Algal Blooms

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Johanna Sigurdardottir Iceland's first female prime minister, the first openly gay prime minister in the world. A Veteran M (longest serving MP) elected in 1978 for the Social Democratic party. Official photo 2009

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Deck chairs under a beach umbrella.

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Handgun on top of the U.S. Constitution

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Dancers at a Cinco de Mayo festival at the Mission District, San Francisco, California. (Photo dated 2019.) holidays

Is Cinco de Mayo Mexico's Independence Day?

Cuban Bee Hummingbird (Mellisuga helenae) single adult male, Zapata peninsula, Cuba, Caribbean.Bee hummingbirds are the smallest birds in the world.

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Young women with rainbow painted faces - symbol of lesbian, gay, bisexual and transgender - LGBT - watch the San Francisco Pride Parade in 2015. Gay pride human rights civil rights spectators California

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marine ecosystem: Facts & Related Content

Written and fact-checked by The Information Architects of Encyclopaedia Britannica

Last Updated: Jun 02, 2025

News •

Scientists identify two global ocean bands heating at record rates • June 1, 2025, 1:24 PM ET (Earth.com)

Facts

Also Known As	ocean ecosystem • sea ecosystem

Photos and Videos

generalized aquatic food web

hydrothermal mussels

palinurid lobster life cycle

Algae, primarily diatoms, dinoflagellates, and coccolithophorids, which are often collectively called phytoplankton, are the base of the food chain for all marine organisms.

Upwelling process along coast

marine food chain

Learn about microplastic and its harmful effect on marine animals

Know about microbead (microplastic) pollution and its devastating effect on marine life

How climate change affects sea life

Know why urinating in the ocean is not chemically damaging to the marine ecosystem

Take an in-depth look at the variety of plankton, from diatoms and microflagellates to jellyfish

See All Videos and Images →

Topics

aphotic zone marine animal hadal zone abyssal zone bathyal zone bottom water littoral zone halocline photic zone deep-scattering layer boundary ecosystem inland water ecosystem pelagic zone

Key People

Timothy Parsons

Canadian biologist

Quiz

Chutes d'Ekom - a waterfall on the Nkam river in the rainforest near Melong, in the western highlands of Cameroon in Africa.

Ecosystems