The oceans cover over three-fourths of the world’s surface, but we still know very little about them. Although from what little we know, we can tell that the oceans and the life within them impact the earth far more than we thought.
Our activities in the past few centuries have had lasting consequences for marine life. We’ve pushed a lot of species to the brink of extinction, and a few others seem to be following suit.
Today, we will discuss some of the most endangered species in the oceans. Let’s dive in…
1. Giant Manta Ray

Giant manta rays are gentle filter-feeding oceanic fish. They can grow up to 7 meters wide and weigh up to 2,500 kg (5,500 lbs).
Giant manta rays are found in warm, temperate, and tropical waters all over the world. They are known for their long migrations and can be found in the open ocean as well as near the coast. They are filter feeders and primarily eat plankton, small fish, and squid. Giant manta rays are also known to jump out of the water – a behavior known as breaching.
Unfortunately, they are classified as a vulnerable species by the International Union for Conservation of Nature (IUCN) due to the significant decline in their population in recent years. The main threats to the giant manta ray are targeted fishing for its gill plates, accidental entanglement in fishing gear, and habitat degradation. Conservation efforts are underway to protect and conserve this species, including the establishment of marine protected areas and regulations on fishing practices.
2. Bluefin Tuna

Bluefin tuna is a highly valued fish, particularly in the sushi market. As such, it has been heavily overfished in recent decades. Bluefin tuna populations have declined by over 80% in some regions since the 1970s. This decline is due to a combination of overfishing, illegal fishing, and the use of unsustainable fishing methods such as longlining and purse seining.
Bluefin tuna is considered to be endangered. The International Union for Conservation of Nature (IUCN) lists the Atlantic bluefin tuna (Thunnus thynnus) as endangered, and the Southern bluefin tuna (Thunnus maccoyii) as critically endangered.
Efforts are being made to protect bluefin tuna populations and promote sustainable fishing practices. For example, the Western Atlantic bluefin tuna population is managed under a quota system, so there are restrictions on the size and age of fish that can be caught. The International Commission for the Conservation of Atlantic Tunas (ICCAT) also regulates the fishing of Atlantic bluefin tuna.
Additionally, there are initiatives to promote the responsible consumption of bluefin tuna and to raise public awareness about the need to protect these fish.
3. Orange Roughy

The Deep-sea Orange Roughy is a fish found in the deep Atlantic Ocean. It is known for its distinctive bright orange color and slender head. It can be found in the Pacific and Atlantic oceans at low temperatures.
Little was known about this fish before commercial fishermen began catching them in the 1970s. Since then, we have learned that they live way longer than was previously thought, with individuals living up to 150 years.
The deep-sea orange roughy is also a commercially valuable fish, which has led to overfishing and a decline in its population. As a result, some countries have imposed catch limits or banned fishing for the species altogether to allow the population to recover. A lot of governments also offer companies willing to buy the fish “sustainable alternatives” to help the fish population recover.
4. Whale Shark

The whale shark is a slow-moving, filter-feeding shark. It is the largest living fish species. It can grow up to 40 feet (12 meters) in length and can weigh over 20 tons. They are characterized by their distinctive patterning of white spots and stripes on a dark background, which is unique to each individual.
Whale sharks are found in warm, tropical waters around the world and feed primarily on plankton and small fish. They are often sought after by divers and snorkelers for ecotourism activities due to their gentle nature.
Despite their popularity with tourists, whale shark populations are in decline. The primary cause of this decline is overfishing, as whale sharks are targeted for their meat, fins, and liver oil. They are also often accidentally caught in fishing gear, such as gillnets and longlines, which can lead to their injury or death. Habitat destruction, pollution, and climate change are other contributing factors to the decline of whale shark populations.
5. Humphead Wrasse

The Humphead Wrasse is a large, brightly-colored fish found in the Indo-Pacific region. It is also commonly called the Napoleon wrasse or Maori wrasse.
Humphead Wrasse is characterized by its large size. They can grow up to 2 meters in length and weigh up to 180 kilograms (or 400 lbs). Another unique characteristic is the big muscular hump on their forehead. They inhabit coral reefs in shallow seas and are very important in maintaining the balance of different invertebrates in their ecosystems.
Valued throughout Asian countries for its meat, overfishing and unsustainable fishing practices have caused the species to decline substantially. The decline in coral reefs throughout the region has also substantially affected their numbers.
Other Types Of Endangered Marine Life
With climate change on the rise, these types of fish aren’t the only marine life fighting to survive. There are many other marine animals that are also facing issues such as a decline in populations, overfishing, and pollution. Some of these are:
6. Hawaiian Monk Seals

Hawaiian monk seals are the only species in the world native to the tropics. They are found in the warm waters around Hawaii, as the name suggests. They have short fur, long snouts, and distinctive fold around their necks that give them a monk-like appearance.
The Hawaiian seal population is extremely endangered, with only around 1,400 individuals remaining in the wild. This decline is primarily due to a combination of human activities, including overfishing, habitat loss, and entanglement in fishing gear. The seals also face threats from climate change, disease, and predation, and have historically also been hunted for their meat.
Despite the challenges facing the species, there are ongoing efforts to protect and conserve the Hawaiian seal population. Conservationists are working to reduce the seals’ interactions with fishing gear and to restore their habitat. Additionally, captive breeding programs have been established to help boost the population and ensure the species’ survival for future generations.
7. Corals

Corals are a species of marine invertebrates. They are closely related to sea anemones and jellyfish. There are 798 known species of corals throughout our oceans. They are critical to the health of the oceans, but most of the population is in steep decline sadly.
Contrary to their ecological niche, they are animals. They begin life as Polyps – small, sea anemone-like animals that attach to a hard surface. As is the case with their close relatives, the polyps have venomous tentacles that they use to catch food. During the day, these tentacles are hidden away, only to come out at night.
Despite making up 0.2% of the ocean’s surface, they support over 25% of marine life in one way or another. Around half of the existent fish species use colonies of corals as nurseries for younglings. Owing to their exoskeletons, they can become very safe habitats for a lot of small fish, making coral reefs and beds a highly nutritious place in the sea.
8. Kemp’s Ridley Turtles

Kemp’s ridley turtle is a critically endangered sea turtle species found primarily in the Gulf of Mexico. They are one of the smallest sea turtle species, with adults typically measuring between 60-70 cm in length and weighing between 36-45 kg. Kemp’s ridley turtles are the only species of turtles that nest during the day.
Unfortunately, Kemp’s ridley turtles are facing significant threats to their survival, and their populations have been declining for decades. With a steep rise in human activity in their habitat, climate change is also threatening their survival.
International conservation organizations like the World Wildlife Fund have been implementing conservation programs for the survival of the species. With the help of local communities and governments, they are sure to be back to their past numbers.
9. Hector’s Dolphin

Hector’s dolphins are one of the smallest and rarest species of dolphins in the world. They are found only in the coastal waters around New Zealand and are known for their distinctive black and white markings, which give them a “mottled” appearance. They are also sometimes colloquially called the Mickey Mouse dolphin due to their round dorsal fin.
Despite their adorable appearances, they’ve been facing a steep decline in population. The North Island subspecies of Hector’s dolphin are critically endangered, with an estimated population of fewer than 100 individuals. The South Island subspecies is listed as endangered, with an estimated population of around 10,000 individuals.
A very low rate of reproduction combined with an increase in human activity has made it very hard for the species to cope. Conservation efforts are underway to protect Hector’s dolphins, including the establishment of marine protected areas and regulations on fishing and boating activities in their habitat. Additionally, educational campaigns are being implemented to raise awareness of the importance of conservation and reduce human impacts on these animals.
10. Vaquita

Vaquitas are the most endangered species of porpoise (a type of marine mammal) in the world. They are only found in a small part of the Gulf of California in Mexico. Vaquitas have a distinctive black ring around their eyes and black patches on their lips, which contrast with their light gray skin. They’re really small, ranging from 1.4-1.5 meters in length.
The main culprit behind their extinction is entanglement in gillnets used by illegal fishing operations in the Gulf of California. The vaquita shares its habitat with the totoaba fish, whose swim bladder is highly valued in Chinese traditional medicine.
Totoaba fishing is illegal, but it continues due to high demand and the high prices that the bladders fetch on the black market. The gillnets used to catch totoaba also accidentally trap and kill vaquitas. It is estimated that there are less than 10 vaquitas left in the wild. This is obviously a cause for alarm as soon there might be none left in the wild at all.