Thursday, May 23, 2024
HomeOcean8 Endangered Marine Animals

8 Endangered Marine Animals

Sadly, over the past 40 years, our world’s marine population has declined dramatically by 50%. Being a diver means that we are not only likely to explore the ocean, we are also advocates and with this said, we have a responsibility to not only be aware of what is threatening our oceans but also to inform others of the daily threats that our oceans face. There are approximately 2,215 species of marine life listed either endangered or threatened according to the ESA (Endangered Species Act).  Here are 8 endangered species that you will find in the ocean and why they are declining at such a fast rate.

How can you help?

Why not watch Racing Exctinction, use their #startwith1thing toolkit to get involved or contact your local marine conservation charity.  Why not tell us about what you are going to do in the comments below?

Blue Finned Tuna

Blue finned Tuna are usually found in the Atlantic Ocean and happen to be one of the most valuable species in the ocean. However, being the most valuable species comes at a steep price. Blue finned tuna have become number one on our endangered species list because of severe over-fishing. There are thought to be only 25,000 blue finned tuna left. Blue finned tuna can reach up to sizes of 2m which is the same as a 6ft man. These giant, warm blooded fish weigh on average 250kg with the largest ever recorded off the coast of Nova Scotia weighing a whopping 679kg.

White Abalone

The White Abalone is found off the coast of California and once flourished. They numbered in the millions and thrived in the cool waters of the Pacific. Unfortunately, nowadays the population of the White Abalone has dropped severely ranging from 1600 to 2000. The reason for their demise has been down to what scientists refer to as a ‘reproductive failure’. The White Abalone release their eggs and sperm out into the water however, as the population has decreased the eggs are less likely to find a sperm and become fertilized. Other reasons for their drop in numbers are due to over-fishing as well as increase in rate of infection. There are however, groups of people who have created breeding programmes to help the White Abalone get back on track.


Known to most as Sea Cows, these gentle giants not only resemble a marine animal, but also a land animal. There are three species of manatee, determined by where they live. One species inhabits the Amazon River, the second species inhabits the west coast and rivers of Africa and the most well-known species of Manatee lives along the North American east coast from Florida through to Brazil. The most recent count of Manatees have seen over 6000 left in existence within the Florida waters.

There are a number of reasons why this beautiful species has deteriorated so rapidly these include; In 2010, a ‘winter freeze’ brutally affected the population of manatees as well as other marine life in Florida. In addition, toxic algae has also wiped out many manatees, this is caused by human pollution entering the rivers and waters in Florida. Another reason for their drop is numbers is down to boating collisions.

Scalloped Hammerhead Shark

The scalloped hammerhead is found virtually all around the world in coastal areas of tropical, subtropical and reasonable climate areas. The IUCN Red List of Threatened Species has reported that the population of Scalloped Hammerheads has declined so rapidly that there is now 50-90% less over the past 30 years. Unfortunately, their decrease in numbers is due to their highly desired fins and with the sheer lack of finning regulations, their numbers have diminished. The Scalloped Hammerheads are also known to be slow reproducers and with this fact, they have been placed on the ‘global endangered’ list. In 2014, these incredibly beautiful creatures were the first species of shark to be protected by the US Endangered Species Act.

Chinook Salmon

The Chinook Salmon is the largest species of the Pacific Salmon genus Oncorhynchus. Salmon is one of the most popular seafood as well as sports fish in the entire world. The Chinook Salmon population found in Alaskan waters stretching to California are in a sharp decline due to a number of reasons. Pollution, is a huge cause of their decline as Chinook Salmon require clean rivers and oceans in order to spawn and survive. Over-fishing, is another cause for this species decrease in numbers. Nine populations of Chinook Salmon are listed as endangered or threatened and are under the US Endangered Species Act.  

Blue Whale

Did you know that the Blue Whale is the largest mammal on the planet? Even though they are the largest as well as the loudest mammal on the planet, their population numbers are dropping considerably. With an average weight of 200 tons and a call that can reach up to 188 decibels, 48 decibels over a jet engine, these extraordinary giants are the kings of the ocean. Unfortunately, due to large scale commercial whaling activities, the worldwide population of the Blue Whale has depleted staggeringly. The most significant drop in Blue Whale numbers occurred in the 1900’s. Another reason why these mind-blowing creatures are not bouncing back is because they have a gestation period of 10-12 months and they tend to reproduce every two to three years. Sadly, the most recent reason for their demise is due to vessel collisions and contact with fisheries. There is however certain organizations such as the NOAA (National Oceanic and Atmospheric Association) who have studied the migration paths of these giants and have managed to divert shipping channels to avoid contact.

Southern Sea Otters

These beautiful little mammals have to be one of the cutest marine animals found off the coast of California. Whilst their cousins who live within the northern sea, off the west coast of the US from Alaska to Washington are thriving with populations over 77,000, the Southern Sea Otter is struggling with as few as 3000 living off the coast of California. The Southern Sea Otter used to number in the hundreds of thousands to the millions, however in the 1700’s to 1800’s they were nearly at risk of becoming extinct because of their fur. Southern Sea Otters have the densest fur on the planet and it is this that can help them to survive in cold waters without a layer of insulating fat. However, their fur is wanted by many and it is this that has caused their demise. In 1911, Sea Otters became protected by the International Fur Seal Treaty as well as being listed under the Marine Mammal Protection and Endangered Species Act in the 1970’s. Since then, their numbers are rising slowly however still fall well below their original numbers. Not only are these amazing creatures vulnerable to their natural predators, they are also effected by Humans as well.

Leatherback Turtles

The Leatherback turtles are named after their shells. Their shells are not like other turtles which are hard, these magnificent marine animals have a shell that best resembles leather. Leatherbacks are by far the largest sea turtle species and also one of the most migratory, crossing both the Pacific Oceans as well as the Atlantic. Their usual path of migration stretches from the ‘Coral Triangle’ to the Californian Coast, where they can feed on copious amounts of jelly fish throughout the summer and autumn months.

Over the last century, the numbers of Leatherback Turtles have declined dramatically, this is due to a concentrated level of egg collecting and bycatching within the fishing industries. According to the IUCN (International Union for Conservation of Nature) Leatherback Turtles are been listed as vulnerable, with many of their subpopulations (Pacific and Southwest Atlantic) of Leatherback Turtles have been classified as Critically Endangered.

Jennifer Palmer
Jennifer Palmer
Diving since I was 13 years old, I am currently a rescue diver working towards my Dive Master qualification. As well as diving, I am also a freelance writer and a professional baker, with my own recipe blog Jennifer's Cakes.


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