Marine ecosystem: Quick Facts

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Last updated

Oct. 9, 2026

Facts

Also Known As	ocean ecosystem • sea ecosystem

Photos and Videos

Diagram showing ocean zonation by depth and region, with labeled layers: littoral, sublittoral, bathyal, abyssal, and hadal along the seafloor, and epipelagic, mesopelagic, bathypelagic, and abyssalpelagic in open water. The littoral zone is at the high-tide mark. Vertical scale marks photic and aphotic zones from surface to 10,000 meters.

Diagram showing the cycling of silica in the marine environment, with arrows illustrating processes such as river influx, inorganic adsorption, biological fixation by radiolarian and diatom skeletons, dissolution, deposition as opaline skeletal debris, upwelling, and hydrothermal activity, all within labeled ocean zones.

A diagram of a generalized aquatic food web shows various marine organisms connected by arrows indicating predator-prey relationships. Top predators like large sharks, smaller sharks, and marlin are at the top, followed by predators such as tuna, squid, lancet fish, and mackerel. Filterers like lantern fish, amphipods, and ocean sunfish occupy the next level, with zooplankton such as shrimp, copepods, and pteropods below them. At the base, phytoplankton including dinoflagellates and diatoms prov

Clusters of hydrothermal mussels with white Galatheid crabs and shrimp grazing on bacterial filaments near a deep sea vent at the Northwest Eifuku submarine volcano in the Mariana Trench.

palinurid lobster life cycle

Illustration comparing a complex ocean food web, with interconnected feeding relationships among marine animals and plankton, to a simple linear food chain showing energy flow from sun to producers, primary consumers, and up to top predators.

Two diagrams compare coastal upwelling during normal conditions and an El Nino event. The top shows strong upwelling with nutrient-rich water and high plankton near the coast, while the bottom shows weak upwelling, a thicker nutrient-poor surface layer, and reduced plankton during El Nino.

Illustration of an ocean food chain showing sunlight supporting one-celled life like dinoflagellates and diatoms, which are eaten by shrimplike copepods. These are consumed by small fish, which are then eaten by mackerel, followed by tuna, and finally a large shark at the top of the food web.

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

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Topics

marine animal aphotic zone hadal zone abyssal zone Today in History—October 20: The Monterey Bay Aquarium Opens bathyal zone bottom water littoral zone halocline photic zone Inland water ecosystem Boundary ecosystem 14 Questions About Aquatic Animals Answered pelagic zone

Key People

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Timothy Parsons

Canadian biologist

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

Ecosystems