Ocean · Coasts · Reefs
Marine Animals
Marine animals include whales, dolphins, sharks, sea turtles, seals and thousands of fish species — many threatened by bycatch, plastic pollution, habitat loss and climate change. This hub links 24 WARN wildlife guides and quick answers on ocean species rescue and welfare.
- 1,000+
- Estimated hatchlings per adult sea turtle that may survive to breed
- ~⅓
- Shark and ray species assessed as threatened on the IUCN Red List Source: IUCN
- Ghost gear
- Abandoned fishing nets continue killing marine life for years after loss Source: FAO / IUCN
Quick answers
- Do sharks die if they stop swimming? Some sharks must keep water moving over their gills to breathe (obligate ram ventilators), but many species can pump water while resting on the seabed. Not every shark dies if it stops swimming.
- What is the difference between a seal and a sea lion? Sea lions have visible ear flaps and can walk on their flippers; true seals have no external ears and move on land by wriggling on their bellies. Both are pinnipeds but belong to different families.
- Are dolphins fish or mammals? Dolphins are mammals. They breathe air through a blowhole, nurse their young with milk, and are warm-blooded — despite living in the sea.
- Why are sea turtles endangered? Most sea-turtle species are threatened by accidental bycatch, illegal egg collection, coastal development, plastic pollution and climate change affecting nesting beaches.
Marine species guides
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Vulnerable
Shark
Sharks are a group of more than 500 species of cartilaginous fish found in every ocean; conservation status varies by species, but about one-third of all sharks, rays and chimaeras are threatened with extinction, mainly because of overfishing, the fin trade and bycatch.
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Not Evaluated
Dolphin
Oceanic dolphins (family Delphinidae) include the common bottlenose and common dolphin — social toothed whales of seas worldwide, distinct from river dolphins; IUCN status ranges from Least Concern to Critically Endangered by species.
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Not Evaluated
Whale
Whales are cetacean mammals (~90 species) including baleen and toothed forms — from the blue whale to sperm whales and orcas; status ranges from recovering humpbacks to Critically Endangered vaquita and North Atlantic right whale.
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Not Evaluated
Orca
The orca (Orcinus orca) is the world's largest oceanic dolphin — a black-and-white apex predator found in all oceans, with pod-specific diets and cultures; globally assessed as Data Deficient on the IUCN Red List.
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Endangered
Blue Whale
The blue whale (Balaenoptera musculus) is the Endangered largest animal on Earth — a krill-filtering baleen whale found in all oceans, recovering slowly after twentieth-century whaling.
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Not Evaluated
Sperm Whale
The sperm whale (Physeter macrocephalus) is a Vulnerable deep-diving toothed whale — the largest brain of any animal — hunting squid in abyssal depths after centuries of commercial whaling depletion.
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Not Evaluated
Narwhal
The narwhal (Monodon monoceros) is a Near Threatened Arctic whale whose males bear a long spiralled tusk — actually an enlarged tooth — with roughly 80,000 individuals dependent on sea ice and deep-water prey.
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Endangered
Sea Turtle
Sea turtles are a group of seven species of large, long-lived marine reptiles whose conservation status ranges from Least Concern to Critically Endangered, with most species threatened by fishing bycatch, egg poaching, plastic pollution and coastal development.
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Not Evaluated
Manatee
Manatees are plant-eating sirenians with three species in the Americas and West Africa — slow-moving mammals threatened by boat collisions, habitat loss and pollution, with IUCN status from Vulnerable to Endangered.
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Vulnerable
Dugong
A dugong is a large, plant-eating marine mammal of the order Sirenia (the "sea cows"), reaching about 3 metres long, that lives entirely in warm coastal seas and feeds almost exclusively on seagrass.
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Not Evaluated
Sea Lion
Sea lions are eared seals (family Otariidae) with visible ear flaps and land agility — about 16 species on Pacific and southern coasts whose IUCN status ranges from Least Concern to Endangered.
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Not Evaluated
Seal
Seals are earless marine mammals (family Phocidae) with about 19 species worldwide — expert divers of polar and temperate seas whose conservation status ranges from abundant to Endangered depending on species and region.
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Endangered
Sea Otter
The sea otter (Enhydra lutris) is an Endangered North Pacific keystone predator that maintains kelp forests by controlling sea urchins — insulated by the densest fur of any mammal, not blubber.
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Not Evaluated
Jellyfish
Jellyfish are gelatinous medusozoans found in all oceans — pulsing drifters using stinging cells to capture prey; most species lack individual IUCN assessments though some face habitat and climate pressures.
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Not Evaluated
Seahorse
Seahorses are upright coastal fish (genus Hippocampus) with ~46 species — males carry eggs in a pouch; many are Vulnerable or Endangered due to habitat loss and huge dried trade for traditional medicine.
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Endangered
Manta Ray
Manta rays are Endangered filter-feeding elasmobranchs — giant and reef species with wingspans up to seven metres — threatened globally by bycatch, gill-plate trade and fisheries.
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Not Evaluated
Stingray
A stingray is a flat-bodied cartilaginous fish in the order Myliobatiformes, related to sharks. Its broad pectoral fins form a disc that flaps for swimming, and most species carry a venomous, barbed tail spine used only for defence. Most are bottom-dwelling ambush predators of shellfish.
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Not Evaluated
Clownfish
The ocellaris clownfish (Amphiprion ocellaris) is a Least Concern anemonefish of the Indo-Pacific, dependent on coral reef and anemone habitat; reef degradation and past wild collection threaten populations.
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Not Evaluated
Pufferfish
Pufferfish (Tetraodontidae) are roughly 200 species of toxic, inflatable fish worldwide; IUCN status varies — Chinese puffer Critically Endangered — threatened by overfishing, habitat loss and bycatch.
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Not Evaluated
Salmon
The Atlantic salmon (Salmo salar) is Least Concern globally but Endangered in much of its southern range; anadromous fish threatened by dams, aquaculture, sea lice, overfishing and river pollution.
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Not Evaluated
Tuna
Atlantic bluefin tuna (Thunnus thynnus) is Least Concern after stock recovery (IUCN, 2021); Southern bluefin is Endangered. Global tuna fisheries face overfishing, bycatch of sharks and turtles, and IUU fishing.
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Not Evaluated
Swordfish
The swordfish (Xiphias gladius) is a Least Concern billfish of global oceans, managed in the Atlantic but overfished in the Mediterranean; longline fisheries cause shark and turtle bycatch.
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Vulnerable
Marlin
The blue marlin (Makaira nigricans) is a Vulnerable billfish of tropical oceans, declining from longline bycatch and overfishing; white and striped marlin face similar pressures.
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Critically Endangered
Eel
The European eel (Anguilla anguilla) is a Critically Endangered catadromous fish spawning in the Sargasso Sea; populations have declined over 90% since the 1970s from dams, pollution, fisheries and illegal trade.