35 Endangered Marine Animals (Explainer Edition)

Curious about which marine species are on the brink? Iconic examples include the vaquita, blue whale, Hector’s dolphin, sea otter, and giant manta ray. Like every ecosystem on Earth, the oceans hold many species with very small populations that are still declining. This guide introduces 35 notable marine species—some rare, some well-known—the threats they face, and practical conservation notes.

Table of Contents

• Vaquita (Phocoena sinus)

• Blue Whale (Balaenoptera musculus)

• Hector’s Dolphin (Cephalorhynchus hectori)

• Irrawaddy Dolphin (Orcaella brevirostris)

• Sea Otter (Enhydra lutris)

• Longhead Eagle Ray (Aetobatus flagellum)

• Giant Manta Ray (Mobula birostris)

• Hammerhead Sharks (family group)

• Whale Shark (Rhincodon typus)

• Kemp’s Ridley Sea Turtle (Lepidochelys kempii)

• Loggerhead Sea Turtle (Caretta caretta)

• Leatherback Sea Turtle (Dermochelys coriacea)

• Bowmouth Guitarfish / Shark Ray (Rhina ancylostoma)

• “Umbrella” Octopus (Cirroctopus hochbergi)

• Narrow Sawfish (Anoxypristis cuspidata)

• Atlantic Bluefin Tuna (Thunnus thynnus)

• Napoleon Wrasse / Humphead Wrasse (Cheilinus undulatus)

• Red Stumpnose Seabream (Chrysoblephus gibbiceps)

• Ocean Sunfish (Mola mola)

• Winghead Shark (Eusphyra blochii)

• Harrisson’s Dogfish (“Puffadder shyshark”) (Haploblepharus kistnasamyi)

• “Gulper Shark” / “Mute Shark” (Centrophorus harrissoni)

• European Eel (Anguilla anguilla)

• Japanese Eel (Anguilla japonica)

• Lined Seahorse (Hippocampus erectus)

• Thorny Seahorse (Hippocampus histrix)

• Japanese Sea Cucumber (Apostichopus japonicus)

• Warty Sea Cucumber (Apostichopus parvimensis)

• Poisonous Cone Snail (Conus ateralbus)

• West Indian Manatee (Trichechus manatus)

• Dugong (Dugong dugon)

• Mediterranean Monk Seal (Monachus monachus)

• Wandering Albatross (Diomedea exulans)

• Atlantic Puffin (Fratercula arctica)

• Corals (incl. deep-sea bamboo coral Isidella elongata)

Note: Phrases like “Critically Endangered/Endangered/Vulnerable” are used in a popular-science sense reflecting the source text and broad consensus. IUCN categories are periodically updated—verify the current listing before publication.

Vaquita (Phocoena sinus)

• Range: Endemic to the Gulf of California.

• Status snapshot: Critically endangered; one of the world’s rarest cetaceans, with extremely few individuals remaining.

• Threats: Gillnet bycatch, habitat pressure.

• Did you know? Smallest porpoise; dark eye patches and lip markings.

Blue Whale (Balaenoptera musculus)

• Range: Global oceans.

• Status snapshot: Still threatened despite protections after commercial whaling; vulnerable to ship strikes, noise, and prey shifts.

• Threats: Historic whaling legacy, ocean pollution, climate impacts on krill.

• Did you know? Earth’s largest animal; the heart is famously enormous.

Hector’s Dolphin (Cephalorhynchus hectori) — incl. Maui subspecies

• Range: New Zealand coastal waters.

• Status snapshot: Endangered and declining.

• Threats: Entanglement in inshore gillnets/trawls, coastal disturbance.

• Note: Short snout, pale facial mask; small, nearshore species.

Irrawaddy Dolphin (Orcaella brevirostris)

• Range: Estuaries and coasts of Southeast Asia (not a freshwater resident, but often near river mouths).

• Status snapshot: Vulnerable and decreasing.

• Threats: Bycatch, pollution, vessel disturbance/noise.

• Note: Rounded head, very short beak, “cute” expression.

Sea Otter (Enhydra lutris)

• Range: North Pacific coasts (North America and far-eastern Russia).

• Status snapshot: Recovering in some areas but still threatened overall.

• Threats: Poaching legacy, coastal pollution, oil spills, climate stress.

• Did you know? A keystone predator that keeps sea urchins in check and protects kelp forests.

Longhead Eagle Ray (Aetobatus flagellum)

• Range: India, Indonesia, Pakistan.

• Status snapshot: Endangered, declining.

• Threats: Incidental capture, nearshore habitat loss.

• Note: Elongated head; graceful “gliding” flight.

Giant Manta Ray (Mobula birostris)

• Range: Tropical–subtropical offshore and coastal waters.

• Status snapshot: Threatened; very low reproductive rate.

• Threats: Bycatch, targeted harvest for gill plates, pollution.

• Note: Wingspan can reach several meters; closely related to devil rays (both are rays).

Hammerhead Sharks (family group)

• Range: Warm seas worldwide.

• Status snapshot: Many species rated CR/EN/VU and trending downward.

• Threats: Overfishing (esp. fin trade), habitat degradation.

• Role: Apex predators crucial for food-web balance.

Whale Shark (Rhincodon typus)

• Range: Tropical to warm-temperate offshore waters.

• Status snapshot: Endangered; slow to reproduce.

• Threats: Fishing pressure, ship strikes, climate-driven prey shifts.

• Note: Largest shark; gentle, filter-feeds on plankton.

Kemp’s Ridley Sea Turtle (Lepidochelys kempii)

• Range: Gulf of Mexico and parts of the North Atlantic.

• Status snapshot: Critically endangered.

• Threats: Bycatch, nesting beach loss, warming affecting sex ratios.

• Note: Famous for synchronized mass nesting (“arribada”).

Loggerhead Sea Turtle (Caretta caretta)

• Range: Warm oceans worldwide.

• Status snapshot: Threatened; significant declines.

• Threats: Bycatch (longlines, trawls), beach development, light pollution.

• Note: Powerful jaws for crushing hard-shelled prey.

Leatherback Sea Turtle (Dermochelys coriacea)

• Range: Highly migratory worldwide.

• Status snapshot: Threatened with steep declines in some rookeries.

• Threats: Bycatch, plastic ingestion (mistaken for jellyfish), nesting beach loss.

• Note: Only sea turtle without a hard bony shell—has a leathery carapace.

Bowmouth Guitarfish / Shark Ray (Rhina ancylostoma)

• Range: Red Sea to Japan and parts of Australia.

• Status snapshot: Vulnerable with a downward trend.

• Threats: Bottom trawling, nearshore habitat pressure.

• Note: Up to 3 m; has a spiny dorsal ridge.

“Umbrella” Octopus (Cirroctopus hochbergi)

• Range: Deep waters off New Zealand.

• Status snapshot: Endangered.

• Threats: Deep-sea fishing disturbance; data deficiency.

• Note: Related to “Dumbo” octopuses; deep-sea cuteness icon.

Narrow Sawfish / Knifetooth Sawfish (Anoxypristis cuspidata)

• Range: Western Pacific–Indian Ocean and Red Sea; coasts of Australia, Japan, New Guinea, Persian Gulf.

• Status snapshot: Threatened (very large, up to 4.7 m).

• Threats: Snout rostrum readily entangles nets; nursery grounds impacted.

• Note: A “sawfish” but more closely related to sharks than to true rays in ancestry.

Atlantic Bluefin Tuna (Thunnus thynnus)

• Range: North Atlantic and Mediterranean.

• Status snapshot: Severely reduced by overfishing; reliant on strict quotas.

• Threats: IUU fishing, intense market demand.

• Note: Endurance athlete of the sea; partial endothermy aids performance.

Napoleon / Humphead Wrasse (Cheilinus undulatus)

• Range: Indo-Pacific coral reefs.

• Status snapshot: Endangered, still declining.

• Threats: Overfishing, reef degradation; protogynous (female-to-male) sex change slows recovery.

• Note: Can live for decades; massive forehead hump.

Red Stumpnose Seabream (Chrysoblephus gibbiceps)

• Range: South Africa’s coasts.

• Status snapshot: Endangered; at risk of disappearing locally in coming years.

• Threats: Local fishing pressure, habitat impacts.

• Note: Prominent forehead; striking red striping; lengths >50 cm.

Ocean Sunfish / Mola (Mola mola)

• Range: Temperate to tropical seas worldwide (surface layer).

• Status snapshot: Vulnerable and decreasing.

• Threats: Bycatch, entanglement in marine debris.

• Note: Often “sunbathes” side-up at the surface—like moonlight on water.

Winghead Shark (Eusphyra blochii)

• Range: Philippines, Australia, China, Persian Gulf (shallow waters).

• Status snapshot: Endangered, declining.

• Threats: Inshore fishing pressure, habitat loss.

• Note: A slender, more extreme “hammer” head.

Harrisson’s Dogfish (“Puffadder shyshark”) (Haploblepharus kistnasamyi)

• Range: South African coast.

• Status snapshot: Endangered; wild numbers are very low.

• Threats: Local fisheries, pollution.

• Note: Pattern recalls the African puff adder—hence the name.

“Gulper Shark” / “Mute Shark” (Centrophorus harrissoni)

• Range: Australia and near New Zealand.

• Status snapshot: Endangered and falling.

• Threats: Targeted for meat and liver oil; deep-sea habitat disturbance.

• Note: Slightly over 1 m; slow-growing deep-sea species.

European Eel (Anguilla anguilla)

• Range: Coasts, estuaries, and inland waters of Europe & North Africa; spawns in the Sargasso Sea.

• Status snapshot: Critically endangered.

• Threats: Overfishing, pollution, dams blocking migration, invasive parasites, climate-driven current changes.

• Note: “Glass eel” juvenile stage is heavily exploited.

Japanese Eel (Anguilla japonica)

• Range: Japan, Korea, Taiwan, China, Vietnam.

• Status snapshot: Endangered, declining.

• Threats: Overexploitation, habitat degradation, altered currents affecting migration.

• Note: Major species for East Asian cuisine; aquaculture depends on wild-caught glass eels.

Lined Seahorse (Hippocampus erectus)

• Range: Western Atlantic (Caribbean–Gulf of Mexico–SE USA).

• Status snapshot: Vulnerable, decreasing.

• Threats: Habitat pollution, illegal aquarium trade.

• Note: Males brood and give birth in a pouch.

Thorny Seahorse (Hippocampus histrix)

• Range: Arabian Sea, Red Sea, southern Indian Ocean.

• Status snapshot: Vulnerable, declining.

• Threats: Habitat loss, trade pressure.

• Note: Spines along the body; camouflages among seagrass and corals.

Japanese Sea Cucumber (Apostichopus japonicus)

• Range: Japan, China, Korea, Russia.

• Status snapshot: Endangered, declining.

• Threats: Overharvest, habitat degradation.

• Note: Economically valuable; “biotills” sediments on the seafloor.

Warty Sea Cucumber (Apostichopus parvimensis)

• Range: Mexico to California.

• Status snapshot: Vulnerable due to fishery demand.

• Threats: Fishing pressure.

• Note: Knobby skin; popular in regional seafood markets.

Poisonous Cone Snail (Conus ateralbus)

• Range: Restricted tropical localities (narrow distribution).

• Status snapshot: Endangered; population reportedly stable in the source text.

• Threats: Habitat disturbance, specimen collecting.

• Safety: Venomous harpoon can cause paralysis and death—never handle.

West Indian Manatee (Trichechus manatus)

• Range: Americas’ Atlantic coasts, Caribbean, Gulf of Mexico.

• Status snapshot: Endangered, significant declines in some regions.

• Threats: Habitat loss, water pollution, boat strikes.

• Note: Gentle herbivores dependent on healthy seagrass meadows.

Dugong (Dugong dugon)

• Range: Tropical shallows of the Indian and western Pacific Oceans.

• Status snapshot: Endangered.

• Threats: Seagrass degradation, illegal hunting, vessel collisions.

• Note: A sea-cow relative; distribution differs from West Indian manatees.

Mediterranean Monk Seal (Monachus monachus)

• Range: Mediterranean and NE Atlantic remnants.

• Status snapshot: Endangered; fewer than 800 individuals reported in the source.

• Threats: Habitat loss, bycatch, disturbance.

• Note: Prefers secluded caves or beaches for pupping.

Wandering Albatross (Diomedea exulans)

• Range: Southern Ocean.

• Status snapshot: Vulnerable; very slow reproduction.

• Threats: Longline bycatch, pollution/marine debris.

• Note: Wingspan up to 3.5 m, the largest among living birds.

Atlantic Puffin (Fratercula arctica)

• Range: North Atlantic (Iceland, Norway, British Isles to Newfoundland).

• Status snapshot: Vulnerable; prey declines (herring, anchovy) harm breeding success.

• Threats: Indirect overfishing effects, climate change, nesting habitat disturbance.

• Note: Colorful bill; adept “flying” underwater.

Corals (incl. deep-sea bamboo coral Isidella elongata)

• Range: Shallow to deep waters in tropical and temperate seas.

• Status snapshot: From Vulnerable to Endangered depending on species; highly sensitive to warming and acidification.

• Threats: Climate change, ocean acidification, pollution, bottom trawling (especially damaging to deep-sea corals like bamboo coral).

• Note: Corals are animals (phylum Cnidaria); reefs shelter thousands of species and serve as nursery grounds.

How Can We Help?

• Cut plastic at the source: avoid single-use plastics; join beach clean-ups.

• Support sustainable seafood: choose certified products; avoid illegal or overfished species (e.g., shark fin, dried seahorses).

• Responsible ocean tourism: observe distance/noise rules for whale-watching and diving.

• Protect nesting grounds and seagrass/coral habitats: never buy coral curios or dried specimens.

• Share science: follow reputable conservation groups; amplify trustworthy information.

Bibliography

IUCN Red List of Threatened Species. Available at: https://www.iucnredlist.org/

Hammerhead Shark Conservation: What You Should Keep in Mind. PADI. Available at: https://blog.padi.com/es/conservacion-del-tiburon-martillo-lo-que-debes-tener-en-cuenta/

Four endangered coral species will be protected in the Mediterranean. OCEANA. Protecting the World's Oceans. Available at: https://europe.oceana.org/es/press-releases/cuatro-especies-de-corales-en-peligro-seran-protegidos-en-el/

animal tags： marine animals