Dolphins are marine toothed whales of the family Delphinidae, they have a beak like snout, a curved dorsal fin, and a slender streamlined body. According to the Endangered Species Act fourteen species of whales and dolphins are considered to be in danger of extinction. Dolphins face a variety of threats to their existence these threats are mainly a result of human activities.
Reasons Why Dolphins Are Endangered
Dolphins are often entangled by commercial fishing gear, this interferes with their ability to breathe and therefore a large number of them die.A number of dolphins are at the verge of extinction from this situation. The Maui’s dolphin are on the brink of extinction due to entanglement in fishing gear. Researchers claim that less than 100 of the Maui’s, a sub-species of the Hector’s dolphin found in the waters of New Zealand remain in existence.
The construction of dams, boat traffic, and related development projects are destroying dolphins river habitats at a very high rate. Recently the Baiji, also known as the Yangtze River dolphin was declared extinct, this incidence was as a result of dam construction and boat traffic.
3) Commercial Harvest
Some dolphin species are harvested as a food source and this contributes in a major way to the decreasing number of dolphins, some fishing boats also accidentally net dolphins while fishing for species like tuna and this also has contributed to threatening the existence of dolphins.
The World Wildlife Federation (2005) suggests that if fishing regulations were changed the porpoises in the Black Sea, Atlantic Humpback Dolphins off the coast of West Africa, and franciscana dolphins in South America could be helped.
4) Climate Change
Ocean temperatures have been rising as a result of climate change. Climate change has also affected ocean currents altering prey distribution, migratory pathway and feeding grounds. This has interfered with dolphins natural habitat posing a threat to their existence
Increasing levels of pollution have also posed major threats to dolphins. Ingestion of marine debris, activity spills resulting from oil and gas development, has led to high rates of dolphin’s deaths. Oil in the sea can make dolphins get hypothermia, this refers to reduction in body temperature which often lead to their death. Oils in some cases blind dolphins reducing their ability to avoid predators which increases their chances of getting killed.
According to the World Wildlife Fund the Western North Pacific gray whale is at serious threat because of intensive oil and gas development in its feeding grounds.