15 Endangered Ocean Species and Marine Animals

According to the International Union for Conservation of Nature (IUCN), hundreds of marine species worldwide are classified as endangered or critically endangered. The IUCN red list determines a species’ status by considering the probability of extinction, breeding levels, current population, and other factors.

Many marine species, including North Atlantic Right Whales, Whale Sharks, Asian Giant Softshell Turtles found in Southeast Asia, porpoises, bluefin tuna, sea otters, manatees, and fur seals, are on the edge of extinction as climate change, habitat loss, and overfishing become a major threat to their existence.

Let’s look at the 15 endangered ocean species and marine animals.

1. Hawksbill Turtle (Eretmochelys imbricate)

It is found in the tropical regions of all the world’s oceans, gulfs and seas- mostly in coral reefs. The Hawksbill Turtle’s population has declined by 80% over the last century.

Known to be a subject of heavy trafficking in the tourist trade in tropical regions for their meat and shells, these turtles have been killed mercilessly.

With their beautiful patterns, the Hawksbill Turtle’s colourful shells make them a valuable item in the market. They are often sold as “tortoiseshells.”

Even though harvesting its eggs is banned in many countries, the practice continues. Its population decline has also resulted from the degradation of coral reefs, which the Hawksbill Turtle primarily feeds on.

According to marine conservatives, this family of turtles is the living representative of reptiles that have existed in our oceans for the past 100 million years. These turtles are also vital for the existence of seagrass beds and coral reefs.

2. Vaquita (Phoeocna sinus)

An inhabitant of the shallow, murky waters off the shore of the Baja Peninsula in Mexico, Vaquitas are the world’s smallest critically endangered cetaceans.

This rare marine mammal is on the brink of extinction only a half-century after its first sighting. Features of Vaquita include the dark rings around their eyes, lips with dark patches, and a thin line from the mouth to the dorsal fins.

Extensive use of gill netting for fishing in the Gulf of California has endangered this marine species, resulting in a gradual drop in population since the 1940s.

Although the gill-netting operation may have ceased in 1970, the population fall persists, at as much as 15% yearly.

According to reports, there are only a dozen of these marine mammals left in the world, and the percentage of decline in their population has been as much as 90% since 2011.

Watch Vaquita’s video here. 

3. Yangtze finless porpoise ( Neophocaena asiaeorientalis)

This species of dolphin is found in Asia’s longest river, the Yangtze in China. According to the World Wildlife Organisation, it is a critically endangered species, and only about 1,000 are left in the world.

In 2006, a close cousin of this species, the Baiji Dolphin, became extinct. This was the first time a dolphin species went extinct due to human activities, especially due to a lack of food caused by overfishing in the river.

Now, the Yangtze Finless Porpoise also faces the same problem. Known for its smile and intelligence, this species also suffers from habitat loss and inadequate food supply.

WWF has connected over 40 floodplain lakes with the Yangtze’s main stem to allow its migration between lakes and the river.

It also tried to work with fishermen to enable them to generate adequate income. This would help tackle overfishing and conserve the finless porpoise in the Yangtze River.

4. Blue Whale (Balaenoptera musculus)

The largest living mammal on earth, the blue whale, belongs to the baleen whales and features more than 100 feet in length and around 200 tonnes in weight.

There are at least three subspecies of Blue whales, and they can be found migrating from both poles in the oceans around the world. At the top of the food chain, whales play a significant role in maintaining a healthy marine environment.

Unfortunately, excessive commercial hunting has drastically decreased the blue whale’s population and threatened its existence even though an international ban was constituted in 1966. According to IUCN’s 2016 estimate, the global population of the Blue Whale is 10,000–25,000.

Watch the blue whale video here.

5. Kemp’s Ridley Sea Turtle (Lepidochelys kempii)

The Kemp’s Ridley sea turtle, also known as the Atlantic Ridley sea turtle, is threatened by oil spills, lack of food, marine pollution, and entanglement in fishing gear.

Primarily found in the Gulf of Mexico, the Kemp’s Ridley sea turtle often migrates to the Atlantic Ocean only to come back to lay eggs. This group of turtles has a unique way of nesting. The female turtles arrive in large numbers- a procession called Arribadas- on a single beach to lay eggs.

Unfortunately, conditions such as loss of habitat, marine pollution, entanglement in fishing nets, and other factors have resulted in the massive decline of the Kemp’s Ridley sea turtle population.

Thus, egg harvesting has been made illegal, and research projects to incubate and hatch eggs in temperature-controlled rooms have been undertaken to save this endangered marine species.

Watch the video of Kemp Ridley Sea Turtle here.

6. North Atlantic Right Whale (Eubalaena glacialis)

This endangered species, which numbers just 366, can be identified by the white calluses, which look quite prominent on its dark grey body. It feeds by swimming through plankton with its mouth open and head slightly above the water surface.

The population was the most affected by the whaling industry, and even after protection, its numbers have not recovered. It is usually found along North America’s Atlantic Coast, the US East Coast, and Canada.

It faces threats from collisions with ships, fishing nets, and even noise produced by ships, making it difficult for them to communicate, find mates and food, and protect themselves from predators.

WWF has taken several steps, such as shifting shipping lanes in the Bay of Funday, to avoid areas where these magnificent creatures dwell. However, these majestic whales are still victims of vessel strikes, which severely injure them. 

7. Steller Sea Lion (Eumetopiasjubatus)

The largest member of the Otariid family and the fourth largest of all seal species, the eared seal can be found in the cold coastal waters of the North Pacific.

Also known as the northern sea lion, the species is named after Georg Wilhelm Steller, a naturalist who first discovered it in 1741.

The high risk of fishing and the harvest by native Alaskans and Canadians for meat, oil, hides, and other by-products make this marine life vulnerable to endangerment.

According to reports, its population has declined by more than 60% due to natural and human threats since the 1960s. However, the eastern Steller sea lion was omitted from the U.S. Endangered Species List in 2013 after increasing population in recent years.

Watch the video of Steller Sea Lions here.

8. Hammerhead Shark (Sphyrna mokarran)

Traced in the tropical regions of the oceans around the world, the Hammerhead shark belongs to the family Sphyrnidae and is given the name because of its “hammer” shaped head.

Hammerhead sharks typically measure 0.9 to 6.0 m in length and weigh up to 580 kg. They are known as aggressive hunters who feed on smaller fish, squid crustaceans, and octopuses. The shark has been reported to attack humans unprovoked.

These migratory sharks are victimised for their fin. Even the process is horrifying as the sharks are caught by fishers, dragged on board, with their fins cut off while they are still breathing.

The remaining carcass is thrown into the water, and eventually, it bleeds to death. Albeit there is a ban on shark finning in many countries, the result has been abortive as the demand and high price paid for it in the Asian market drive the illegal harvest system, endangering these marine species’ survival.

9. Blue Fin Tuna (Thunnus Thynnus)

The biggest tunas, weighing about 1500 pounds, they can live for four decades. They are excellent predators, seeking out eels, mackerels and herring. 

These fish migrate across the oceans and can dive deeper than 3000 ft. They are known for their remarkable speed and great eye-sight, which makes them the sharpest among all bony fish. 

The Atlantic Bluefin tuna is the biggest and most endangered species. Two other species are the southern and Pacific Tuna.

The majority of Atlantic bluefin catches are from the Mediterranean Sea, as this fish is considered a delicacy for sashimi and sushi. A single Atlantic bluefin is sold for more than 1.75 million dollars!

Hence, they provide livelihood to people, but they are not just fish but also top predators in the aquatic food chain, which maintains a balance in the ocean ecosystem.

Illegal fishing of this species is a major issue, and many environmental organisations are working to prevent this.

10. Fin Whale (Balaenopteraphysalus)

Also known as the common rorqual, the Fin whale is the second-largest mammal on the planet after Blue Whale. With a maximum length of 25.9 meters, the Fin Whale weigh about 114 tonnes.

Like all the other whales in our oceans, the Fin Whale is also a victim of hunting. According to estimates, the global population of Fin Whale ranges from below 100,000 to around 119,000.

Humpback Whale, another rorqual species, has also been listed as an endangered marine species. Before the introduction of the whaling moratorium in 1966, these species were hunted for their fur and flesh for meat, while the population dropped by 90%. Currently, around 2,500 Humpback Whales survive in the world.

11. Hector’s Dolphin (Cephalorhynchushectori)

Found off the coast of New Zealand, Hector’s Dolphins are the smallest dolphin in the world and the most prominent dolphin in the genus Cephalorhynchus.

Mostly sighted around the South Island, the world’s rarest dolphins’ features include black markings on the face, stocky bodies, and creamy white throat and belly. One group of Hector’s Dolphin is made of two to eight members.

Unfortunately, there is a significant decline in their population as trawl fisheries and bottom-set gill nets cause the death of these species. Most deaths happen in the fishing nets.

One of the two sub-species of Hector’s Dolphin, Maui’s Dolphin, is considered the most endangered. According to the survey conducted by the New Zealand Department of Conservation in 2010-11, the estimated population of these dolphins is 55.

12. Hawaiian Monk Seal (Monachusschauinslandi)

A native of the Northwestern Hawaiian Islands, the Hawaiian Monk Seal is one of the earless seals that live on warm beaches, unlike other seals.

This endangered marine mammal is one of the two remaining seal species—along with the Mediterranean monk seal. The third species from this family, the Caribbean monk seal, has already disappeared from the planet.

According to recent research, only 1,400 Hawaiian Monk Seals remain on the Islands. These seals are threatened by commercial hunting for meat, oil, and skin, attack from predators including tiger sharks, marine debris, and entanglement in fishing nets.

13. Whale Shark (Rhincodon typus)

The biggest sharks travel massive distances to get enough food. They are found in all tropical oceans, and the white spots on their bodies make them easily recognisable. They can be as long as 20 metres and weigh around 11 tonnes.

Adult whale sharks feed at the surface, and though they live alone, they can gather in places where abundant plankton is available, making them a tourist attraction.

Though protected from fishing in several nations, their population is declining due to the international demand for their meat, oil, and fins. They are often caught in fishing nets and can be injured by ship propellors. 

Organisations like the WWF use satellite tags, cameras, and other devices to track and study their behaviour in the Coral Triangle. They also work to raise awareness among tour boat operators and tourists about these gentle giants.

14. Green sea turtle (Cheloniamydas)

One of the largest sea turtles, the Green Sea Turtle, is a herbivore in the tropical and subtropical seas. The species is named after the colour of the fat found underneath its carapace. Like many other turtles, Green Sea Turtles migrate from hatching beaches to feeding grounds.

Since these sea turtles are a popular food, the hunt for turtles and their eggs threatens their lives. The loss of sandy beaches and careless fishing have reduced their population.

Apart from these mammals and turtles, salmonids and seabirds have also confronted the menace of endangered ocean species.

The Maritime Mammal Protection Act (MMPA-1972) and The Endangered Species Act (ESA-1973) have significantly salvaged this ocean life. Still, adequate awareness of these issues and the transcendence of human behaviour following that can inevitably make a difference for these ocean-endangered species.

15. Humphead Wrasse (Cheilinus undulatus)

This massive coral reef fish can grow more than 6 feet and weigh 400 pounds. It has a bulge on its head and roams near reefs, searching for its prey, like molluscs, crustaceans, and starfish. Some can even live more than 30 years. 

WWF has urged governments in the Coral Triangle to prevent the trade and consumption of this fish, which is considered one of the most costly reef fish.

The illegal trade in Southeast Asia threatens the Humphead Wrasse, as poachers resort to destructive and harmful methods to catch them.

The Humphead Wrasse is vital for the health of coral reefs as it consumes starfish and controls the population of this coral reef predator.

WWF helped stop the export of this fish in Malaysia and partnered with other organisations to repopulate protected reefs with humphead wrasses. 

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About Author

Zahra is an alumna of Miranda House, University of Delhi. She is an avid writer, possessing immaculate research and editing skills. Author of several academic papers, she has also worked as a freelance writer, producing many technical, creative and marketing pieces. A true aesthete at heart, she loves books a little more than anything else.

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