Marine animals around the world are suffering from detrimental practices like overfishing, bycatch, and habitat destruction. Historically, species like the blue whale were hunted to the brink of extinction, and to this day, they still have not recovered. These species have been categorized as either endangered or critically endangered by the IUCN and can be explored below.

River Dolphins 

Conservation Status: Vulnerable to Critically Endangered

Location: Amazon, Orinoco, Ganges, Indus, Yangtze, Irrawaddy, Mahakam, and the Mekong rivers

Major Threats: Habitat destruction, pollution, agriculture/irrigation, competition

Two river dolphins with small eyes
Two river dolphins with small eyes

Credit: Auch

River dolphins are a group of mammals that live in fresh and brackish water. The term “river dolphin” includes several superfamilies and families. Today, there are five extant, or living, species. 

River dolphins are smaller than other species. They range from around five feet long to eight feet long. The largest species is the Amazon river dolphin which can weigh up to 220 pounds. They have streamlined bodies, as all dolphins do, but ones that have evolved to live in shallow water with strong currents. They are restricted to very specific areas. This is one of the primary reasons for their declining numbers. 

Historically, breeding these unique dolphins has been unsuccessful and very few of these incredible creatures are in captivity. In the wild, they are threatened by human encroachment on their limited territory, agricultural practices that change and pollute rivers, competition from large fish (which are plentiful especially in the Amazon river), and pollution due to industrialization and runoff. 

Blue Whale 

Conservation Status: Endangered

Location: All oceans, except the Arctic

Major Threats: Habitat loss, pollution, vessel strikes, entanglement with fishing gear

blue whale
Blue whale swimming near the surface of the water

The blue whale is part of the baleen whale parvorder Mysticeti, also known as whalebone whales. It is famed as the largest creature ever to live on planet Earth. 

They are large, slender whales that have grey-blue in color. Their bodies are often mottled, with different patterns appearing on individuals. Their heads are large, broad, and flat with a “U” shape when seen from above. The largest recorded blue whale was 196 long tons, as many as thirty-three elephants. 

The whales are threatened by vessel strikes in the open ocean and entanglement with fishing gear. Organizations around the world are working to prevent these avoidable deaths. They also suffer from habitat loss and pollution, and historically, hunting. These whales, like other species, were hunted without regard for the survival of the species throughout previous centuries. Around 340,000 blue whales were killed in the early 20th century. 

Giant Devil Ray 

Conservation Status: Endangered 

Location: Mediterranean Sea and East Atlantic 

Major Threats: Bycatch

Giant Devil Ray
A Giant Devil Ray

Credit: Patrik Neckman

The giant devil ray is a large ray that can reach widths of around 11 feet. It is one of the largest ray species. The species is also sometimes referred to as the “devil fish.” They are threatened due to bycatch. This occurs when fishermen are trawling for a specific type of fish with a large net but end up catching many different species they weren’t looking for. 

Most devil rays live in the Mediterranean Sea but they also reside in the Eastern Atlantic Ocean, around the coast of Ireland, and south of Portugal. 

Galápagos Penguin 

Conservation Status: Endangered

Location: Galápagos Islands, Ecuador

Major Threats: Predation and climate change

juvenile galapagos penguin
Juvenile Galápagos penguin

Credit: Aquaimages

The Galápagos penguin is native to the Galápagos Islands, Ecuador, and is the only penguin living north of the equator. This remarkable creature is also one of the smallest penguins. They have features on their backs, flippers, and head and have developed unique techniques to survive in their warm environment. 

Predation is one of the major threats to the population. It has greatly reduced the estimated life span of these penguins (which should be around 15-20 years). The penguins are also threatened by environmental changes, like warming ocean temperatures. Predators include cats, dogs, rats, snakes, crabs, sharks, fur seals, sea lions, owls, and hawks. 

There are believed to be around 1,200 mature Galápagos penguins left in the world, according to a 2018 study. 

Shortfin Mako Sharks 

Conservation Status: Endangered

Location: Temperate and tropical seas around the world

Major Threats: Fishing and bycatch

the head of a shortfin mako shark
Head of a shortfin mako shark

The shortfin mako sharks, also known as blue pointer or bonito sharks, are a large species of mackerel sharks. The shortfin species grows to around thirteen feet, or four meters, in length. The species is endangered due to fishing practices, both sport, and commercial. It is also threatened by bycatch. 

Hawksbill Sea Turtle 

Conservation Status: Critically Endangered

Location: Oceans worldwide 

Major Threats: Overfishing

Hawksbill sea turtle
Hawksbill sea turtle

Credit: Thierry Caro

The hawksbill sea turtle is a critically endangered species. It has a flattened body, flippers, and a sharp curving beak. They weigh around 180 pounds on average and grow to lengths of around three feet. The turtles live part of their lives in the open ocean and part around coral reefs. They are endangered due to fishing practices. The turtle shells are often used for decorative purposes. 

North Atlantic Right Whale

Conservation Status: Critically Endangered

Location: North Atlantic Ocean

Major Threats: Entanglement with fishing gear, vessel strikes 

North Atlantic right whale beached in the 19th century
North Atlantic right whale beached in the 19th century

The North Atlantic right whale is one of the most endangered species in the world. Estimates suggest there are around 350 individuals left in the world. Commercial whalers hunted these incredible creatures to the brink of extinction in the early 1890s. Today, the greatest threat the whales face is from vessel strikes and entanglement in fishing gear. 

Humphead Wrasse 

Conservation Status: Endangered 

Location: African coast, Indian and the Pacific Ocean

Major Threats: Fishing and habitat destruction

Humphead wrasse in an aquarium
Humphead wrasse in an aquarium

Credit: Mokkie

The humphead wrasse is an endangered species that is also sometimes known as the Napoleon fish or the Māori wrasse. The fish is the largest member of the Labridae family, with males reaching around two meters in length and weighing up to 180 kilograms or almost 400 pounds. It has large lips, a bulbous head, and blue-green coloring. They are threatened by destructive fishing practices, habitat loss, fishing for food, reef fish trade, and more. 

Scalloped Hammerhead Shark

Conservation Status: Critically Endangered

Location: Warm waters worldwide

Major Threats: Overfishing

Scalloped hammerhead shark
Scalloped hammerhead shark

Credit: Barry Peters

The scalloped hammerhead shark is a species of hammerhead that is also known as the southern hammerhead or the bronze hammerhead. It lives in warm, tropical waters around the world. It is the most common species of hammerhead shark. The male sharks weigh around sixty-four pounds and grow to lengths of approximately six feet. Females are longer, reaching lengths of up to 8.2 feet and weighing around 180 pounds. The sharks are categorized as critically endangered by the IUCN. This is primarily due to overfishing. 

Whale Shark 

Conservation Status: Endangered 

Location: Open waters of tropical oceans

Major Threats: Overfishing, bycatch, vessel strikes. 

Whale shark
Whale shark swmiming

The whale shark is a large species of shark that is also the largest nonmammalian vertebrate. The biggest whale shark ever recorded reached 61.7 feet or 18.8 meters. The shark’s head is large and flat with small eyes and five large pairs of gills. The sharks are also noted for their dark grey skin that’s covered with pale grey or white spots and stripes. They are slow-moving filter feeders that are endangered due to vessel strikes, by-catch, fishing, and more. 

FAQs 

What is the most endangered marine?

Today, there are numerous endangered marine species. But, one of the most endangered is the vaquita. This is a small mammal of which there are only thought to be around ten remaining specimens. 

How many marine species are currently endangered?

Today, the ICUN lists 2,270 marine species are endangered. Around 150 of these live in the waters around the U.S. Many of these species are critically endangered while others are going to be easier to recover. 

What ocean animals are endangered?

Many ocean animals are endangered, from the sea turtle to the whale shark, and the dugong. Others include the Galapagos penguin and the scalloped hammerhead shark.