Sadly, many marine species are fighting for survival due to human interference. Poaching, climate change, pollution, oil spills, boat collisions and bycatch are all man-made issues that are pushing our marine wildlife to the brink of extinction. Our oceans and aquatic species are crucial to the planet’s complex web of life, and the disappearance of even a single species can severely affect the whole ecosystem. In short, the world needs our sea life to survive.


We have identified the world’s most endangered marine species. For more information on the world’s most endangered species and how to protect our wildlife, visit the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species.

1. Vaquita (Phoeocna sinus)

The vaquita is the world’s rarest sea mammal and one of the most endangered animals in the world. Their name means ‘little cow’ in Spanish, and they are a unique species of porpoise, with a small, chunky body and a round head. Their eyes and lips are coloured with dark markings, giving them the appearance of wearing makeup. With less than 30 individuals left, the vaquita is critically endangered and facing imminent extinction. They live in only one body of water in the Gulf of California and reproduce only once every two years, however it’s humans that have caused the most destruction to the vaquita population. Up to 15% of vaquitas die in fishing nets every year, and the species is also threatened by the use of chlorinated pesticides. In response to the threat, the Mexican government banned the fatal gillnets, however illegal fishing still occurs, and the vaquita population continues to plummet.

2. Whale Sharks (Rhincodon typus) 

Whale sharks are the biggest fish in the ocean, known to grow up to 18 metres long, weigh up to 19,000 kilograms and live for 70 to 130 years. Each whale shark has unique polka-dot markings on their body, similar to a human fingerprint. They have mouths that are nearly a metre wide, with more than 350 rows of teeth, but these gentle giants feed mainly on plankton, using their mouths as a filtration system. As of 2016, these beautiful creatures have been classified as endangered on the IUCN Red List of Threatened Species, with an alarming reduction in sightings. Their disappearance is largely due to commercial fishing and illegal poaching, with demand coming largely from China for their meat, fins and oil which are sold for food, and their skin for bags.

3. Hawksbill Sea Turtle (Eretmochelys imbricate)

The Hawksbill sea turtle is one of the smallest species of turtle, distinguished by their stunning gold and brown patterned shells (known as tortoiseshell). The Hawksbill sea turtle is the most endangered species of turtle in the world, and is classified as critically endangered by IUCN, with an estimated global population of 8,000, with only 1,000 nesting females. Unfortunately, the turtles are hunted for their beautiful shells, which are sold illegally to create jewellery and ornamental products. The commercial trade of tortoiseshell was banned in 1973, however these products, such as earrings, necklaces, sunglasses and bekko combs (used in traditional Japanese wedding dress), are still widely sold across the Caribbean, Asia and Central America.

4. Sea Otter (Enhydra lutris)

The gorgeous sea otter is one of the smallest marine mammals on earth, and they play a crucial role in our ecosystem, feeding on sea urchins which allows kelp forests to thrive. They’re an incredible species, boasting an impressive string of skills. Sea otters can live their entire life without leaving the water; they are one of the few species on earth that use tools to survive (they use rocks to hammer shells open); they are the only marine mammal that can flip boulders over on the sea floor; they consume between 25 to 40% of their body weight everyday; and they adorably hold hands while they sleep, to keep from drifting apart.

They also have the densest fur of any creature on earth, with around 1 million hairs per square inch. Unfortunately, their beautiful fur is also their biggest threat, due to rampant hunting by humans for sea otter pelts. Their populations once numbered over several hundred thousand, however their numbers plummeted to less than 2,000 due to the fur trade. Since the international ban on large-scale commercial hunting in 1911, numbers have increased to just over 100,000. Sadly, the sea otter is still classified as endangered by the IUCN, due to other threats such as pollution, oil spills and entanglement in fishing equipment.

5. Florida Manatee (Trichechus manatus)

Manatees are one of nature’s goofiest creatures, with short snouts and chunky bodies. Also known as sea cows, these creatures aren’t fat – their large bodies are actually packed with organs. They are the ocean’s largest herbivores, growing up to four metres in length, weighing around 600 kilograms, and eating 10 to 15% of their body weight each day. These sweet giants have no natural predators (only humans) and even coexist peacefully with alligators. Sadly, manatees are an endangered species due to boat collisions, entanglement in fishing gear, and habitat pollution. The current population is estimated to be around 6,000 individuals.

The Manatee Sanctuary Act in the US prohibits the disturbance of these creatures, however a total of 804 manatees died in Florida waters in 2018, with boat collisions causing 119 of these deaths. The toxic algae crisis was also reported to have caused around 100 manatee deaths in 2018.

6. Galapagos Penguin (Spheniscus mendiculus)

As the only penguin species found north of the equator and in the Galapagos Islands, this penguin is quite unique. It’s the smallest of the South American penguin species, and generally survive for 15 to 20 years in the wild. They are one of the few animals in the world that mate with one partner for life. The Galapagos penguin is an endangered species, with less than 2,000 left in the wild. They’re numbers are severely declining due to warming sea temperatures and declining food sources, brought on by El Nino Southern Oscillations (an irregular variation in winds and sea surface temperatures).

They are also threatened by introduced species such as dogs and cats, pollution and bycatch in fishing equipment. The Galapagos fur seal is another fascinating marine species that’s endemic to the Galapagos Islands. With a declining population of around 10,000 to 15,000, the fur seal is also classified as endangered by the IUCN.

7. Hawaiian Monk Seal (Monachus schauinslandi)

Native to the Hawaiian islands, the Hawaiian monk seal is one of only two mammals that are endemic to Hawaii (along with the Hawaiian hoary bat). While most seals live in cold regions, this unique species prefers to live in a tropical climate. They are also one of the last two surviving monk seals on earth (including the Mediterranean monk seal), and have been classified as an endangered species since 1976. Although tiger sharks and Galapagos sharks are known to hunt Hawaiian monk seals, their biggest predators are humans.

There are only around 1,400 remaining Hawaiian monk seals, and the Hawaiian government is working to protect these animals and stop people harming them. The development of coastline has threatened their habitats, and they also have one of the highest rates of entanglement in fishing equipment out of all marine mammals.

8. Fin Whale (Balaenoptera physalus)

Also known as common rorqual, Fin whale is the second-largest mammal on the planet after Blue Whale. With a maximum length of 25.9 meters, the Fin Whale has an estimated weight of about 114 tonnes. Like all the other whales in our oceans, the Fin Whale is also a victim of hunting for a long period of time. 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 whaling moratorium in 1966, these species were hunted to extinction for its fur and flesh for meat, while the population dropped by 90%. Currently, around 2,500 Humpback Whale is believed to surviving in the world.

9. Steller Sea Lion (Eumetopias jubatus)

Evidently the largest member of the Otariid family and the fourth largest of all seal species, this eared seal could be located 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 them in 1741.

The high risk of predation by Killer Whales and fishing and harvest by native Alaskans and Canadians for meat, oil, hides and other by-products make this marine life vulnerable to endanger. According to reports, its population has declined by more than 60% due to both 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 their increasing population in recent years.

10. Hammerhead Shark (Sphyrna mokarran)

Traced in the tropical regions of the oceans around the world, the Hammerhead shark belongs to the family Sphyrnidae and was given the name because of its “hammer” shaped head. The Hammerhead sharks typically have 0.9 to 6.0 m length and up to 580 kg weight. Known as aggressive hunters, these sharks are feed on smaller fish, squid crustaceans and octopuses, while there are reports of unprovoked attacks on humans by the shark.

These migratory sharks are subjected to being victimized for its fin. Even the process itself is horrifying as the sharks are caught by fishermen, dragged on board and is cut off their fins while they are still breathing.The remaining carcass is thrown into the water and eventually, it bleeds to death. Albeit there is a ban imposed upon shark finning in many countries, the result has been abortive as the demand and high price paid for it in the Asian market drives the illegal harvest system, endangering these marine species’ survival.


Apart from these mammals and turtles, salmonids and seabirds also have confronted the menace of endangered ocean species. The Maritime Mammal Protection Act (MMPA-1972) and The Endangered Species Act (ESA-1973) have contributed so far to salvage this ocean life but it requires adequate awareness about these issues and the transcendence of the human behaviour in accordance to that, which can inevitably make a difference for these ocean endangered species.