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Endangered Ocean Animals


Hundreds of ocean animals probably are on their way to extinction. To find a solution and prevent these extinctions, you need to know the causes of the problem. Here are:


8 Ways Ocean Animals Become Endangered


  1. Climate change. Climate change affects marine (An ecosystem is made up of living organisms and their physical environment.) Threats include rising sea levels and an increase in acid levels of seawaters.


Sea turtles, which are an endangered species, are harmed by climate change. Turtle eggs require an external source of heat for incubation—that is, to maintain the proper temperature for their eggs to develop and hatch. For sea turtles, the incubation temperature determines the sex of the hatchlings. Warmer temperatures tend to produce females, while cooler temperatures produce males. Scientists fear that global warming will cause too many female turtles to be born, causing sex ratios to be skewed. Also, as sea levels rise, sea turtles will have less beach area on which to nest.


  1. Disease can devastate ocean animal populations.


The populations of staghorn and elkhorn corals have collapsed since about 1980, in part because of disease. Corals are stationary marine invertebrates related to jellyfish and sea anemones. A bacterial disease called white-band disease affects the staghorn and elkhorn corals, which are found in the Caribbean Sea and other places. This disease destroys the coral’s exoskeleton (exterior covering).


  1. Habitat disturbance. Some ocean animals are endangered because humans disturb the animal’s natural habitat.


Part of the reason that the right whale is endangered is because of habitat disturbance. The right whale is a large whale that may reach 60 feet (18 meters) in length and can weigh up to 100 tons (90 metric tons). The long-distance communication systems of right whales are disturbed by sonar systems used by the United States Navy. These systems use sounds to make measurements and identify underwater objects. The sonar seems to confuse and frighten the whales, causing them to behave abnormally. Some whales stop eating or try to escape the sounds by beaching themselves.


  1. Habitat loss. When we think of habitat loss, we generally think of loggers destroying forests or farmers turning natural grasslands into pasture for their livestock. However, habitat loss also affects ocean animals.


Two sawfish species are partially endangered because of habitat loss. Sawfish are a kind of boneless fish called rays with a long snout that resemble a saw. Sawfish live in warm waters, typically near shorelines. Unfortunately, human developments have destroyed some vegetated coastal habitats, such as mangrove forests, where young sawfish live. According to some scientific estimates, the population of the smalltooth sawfish, one of the seven species of sawfish, has declined by at least 95 percent since the mid-1900’s.


  1. Some ocean animals are hunted for food or for their fur.


Hammerhead sharks are meat-eating sharks that have a wide, flattened head. In most species, the head resembles a hammer. These sharks are killed for their large dorsal fins, skin, and meat. The fins are used to make shark-fin soup. The skin is made into leather. The meat is used for food or to make “fish meal” (used as fertilizer and as feed or poultry). The liver oil is made into vitamin supplements.


  1. Overfishing is a problem for many fish. The fishing industry has harvested many kinds of fish faster than the fish stocks have replaced themselves.


The Atlantic Bluefin tuna is endangered because of overfishing. The Atlantic Bluefin tuna is the world’s largest tuna, growing as much as 14 feet (4.3 meters) long and weighing up to 1,600 pounds (730 kilograms). Tuna are among the most popular food fish in many countries, and the tuna’s fighting ability makes them popular sport fish. Unfortunately, their popularity has led to overfishing. The overfishing of tuna has also put dolphins at risk, since large nets that catch tuna often trap and kill dolphins as well.



  1. Pet trade. Part of the reason some fish are endangered is because they are captured for home aquariums. In fact, most saltwater fish found in aquariums are caught in the wild.


The Asian arowana, or dragonfish, is a freshwater tropical fish that is now endangered, in large part because people desire them for their home aquariums. The population of clownfish in the wild has dropped dramatically since the release of the movie Finding Nemo. While their numbers have dropped, clownfish are not considered “endangered” because many of them are bred in captivity.


  1. Pollution. Humans have spewed industrial, agricultural, and chemical pollutants; sewage; and garbage into the oceans; all of which poison animals. Oil spills have polluted beaches, ocean waters, and the ocean floor. The vast majority of marine debris consists of small pieces of plastic from common objects, such as plastic bottles or bags. Plastic litter on land can be carried to the ocean by water or wind. People continually dump other toxic materials into the sea.


Oil pollution is an especially serious problem for penguins. Even a small amount of oil in the ocean is harmful to the birds. It robs their feathers of the ability to keep the birds warm. When the penguins try to clean their feathers, they swallow the poisonous oil.



For more information about what you can do to help ocean animals, see National Geographic – The Ocean Initiative (


(Photo Credit: © Martin Prochazkacz, Shutterstock)




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