Dolphin Threats
What are the most pressing dolphin threats of today?
Worldwide, dolphins face a variety of impacts that are threatening their existence. Most pointedly, and primarily dolphin threats are a result of human activities and their related impacts. In recent history the Baiji, also known as the Yangtze river dolphin, was declared critically endangered, its river habitat ruined by the construction of dams and the invasion of boat traffic.
Similarly, endangered dolphins like the Maui’s dolphin are on the brink of extinction due to entanglement in fishing gear. The Maui’s, a sub-species of Hector’s dolphin found in the waters of New Zealand, are teetering on the brink, with current estimates suggesting fewer than 100 members remaining in existence.
Some other dolphin species that are at risk of extinction include:
Irrawaddy Dolphin
The Irrawady dolphin is an oceanic dolphin found on the coasts and estuaries and rivers in the Bay of Bengal as well as Southeast Asia. They are closely related to the Australian snubfin dolphin. It is unknown the number of adult individuals, but according to the IUCN Red List, they were last assessed in August of 2017 and listed as “endangered” with a decreasing population.
Australian Snubfin Dolphin
The Australian snubfin dolphin is found in the waters along the northern coast of Australia up to Papua New Guinea. They are listed as a “vulnerable” species on the IUCN Red List. It is estimated that 9000-10000 individuals exist in the wild, but on a decreasing trend.
Hector’s Dolphin
Found in the waters surrounding most of New Zealand, the Hector’s dolphin has not been assessed on the IUCN Red List since 2008. At last estimation, the number of mature individuals was around 7381, however, that could be drastically different. The trend at the time was a declining population, and that is likely still the case.
South Asian River Dolphin
In the rivers of South Asia, exists a river dolphin that is at great risk. The South Asian river dolphin is broken up into two subspecies – the Ganges river dolphin and the Indus river dolphin. While the populations are unknown, they have been listed as “endangered” and on a declining trend.
Australian Humpback Dolphin
Also found in the oceans across the North of Australia and up to Papua New Guinea, the Australian humpback dolphin has been globally assessed as a “vulnerable” species on the IUCN Red List. It is estimated only 10000 individuals exist in the wild and are on a decreasing trend as of the last assessment in May 2015.
Amazon River Dolphin
Throughout the Amazon Basin is the infamous Amazon river dolphin. These dolphins are well known for their pink colour. According to the IUCN Red List, the dolphins were last assessed in June of 2018. The number of mature individuals is not listed, however, it is expected that they are on a declining trend as they face many threats. They have been listed as an “endangered” species.
Indian Ocean Humpback Dolphin
This species of dolphin is located throughout the Indian Ocean and the coasts along it. The Indian Ocean humpback dolphin is also an endangered species with an unknown number of mature individuals. They are listed on the decreasing trend as well.
Atlantic Humpback Dolphin
The Atlantic humpback dolphin is found along the west coast of Africa. They are listed on the IUCN Red List as “critically endangered” with less than 1500 mature individuals estimated to be in the wild. The numbers are decreasing and were last assessed in March of 2017.
Dolphins are also faced with other threats such as pollution of the environment, climate change, and commercial harvest.
Entanglement
Like whales, dolphins are susceptible to entanglement in commercial fishing gear. Discarded fishing gear also poses a major threat. Entanglement drowns dolphins when they are unable to reach the surface to breathe. A number of dolphin species are on the verge of extinction for this very reason.
Dolphin Habitat Loss
River dolphins share their habitat with a large percentage of the world’s population which is threatening their existence. The construction of dams, boat traffic, and other waterfront development are destroying their river habitats at an alarming rate.
Commercial Harvest
Some dolphin species are harvested as a food source, despite containing toxic levels of contaminants such as mercury in their flesh. These contaminants have been directly linked to illness and disorders in humans who consume them. The most talked about dolphin harvest occurs in Japan and can be further explored in the documentary, The Cove (trailer here).
Also, be sure to watch the video below, and learn about one of the leading organizations working toward saving dolphins and their natural habitat.
Climate Change
Climate change has a multitude of effects on the oceans which is having an adverse impact on marine mammals such as dolphins and could become the biggest of all dolphin threats. As ocean temperatures rise from climate change, prey populations can be affected. Climate change also affects ocean currents altering prey distribution, feeding grounds, and migratory pathways.
Other dolphin threats include capture for the highly controversial marine park industry, the ingestion of marine debris, activity and spills resulting from oil and gas development, disturbance by recreational watercraft, and noise pollution.
Other threats include residential & commercial development adjacent to important coastal habitats, aquacultural non-timber crops, and invasive species and diseases.
Ways to help
As an educated traveler, you can make important decisions about the tours you take, places you stay, and the ways you travel that are non-invasive to dolphin species. Choosing not to swim with dolphins or visit attractions that exploit them will contribute to the fight against dolphin captivity. It is our hope that through sharing and education, these species will not experience extinction. Join a large community of like-minded travelers by taking the KEEPitWILD Pledge to keep wildlife wild!
You can learn more about dolphin facts, here.
Read a guest post “Loving Dolphins to Death in Zanzibar” from Rebecca Hamilton.
