Nearly 6,000 rare Irrawaddy dolphins have been discovered living in and around Bangladesh’s Sundarbans mangrove forest and adjacent waters of the Bay of Bengal
A HUGE population of nearly 6,000 rare Irrawaddy dolphins has been discovered living in freshwater regions of Bangladesh’s Sundarbans mangrove forest and adjacent waters of the Bay of Bengal, according to the Wildlife Conservation Society (WCS). The Irrawaddy dolphins, which are related to orcas or killer whales, were listed as vulnerable in the International Union for Conservation of Nature Red List in 2008. These dolphins grow to some 6.5-8 ft in length and tend to frequent large rivers, estuaries, and freshwater lagoons in South and Southeast Asia. In Myanmar’s Ayeyarwady River, these dolphins are known for ‘cooperative fishing’ with humans, where the animals voluntarily herd fish toward fishing boats. Despite this large population, the report warns that the dolphins are increasingly threatened by accidental entanglement in fishing nets. In a second paper, the researchers listed the additional long-term threat to the dolphin population of declining freshwater supplies, caused by upstream water diversion in India, coupled with sea-level rise due to climate change. The likely extinction of the Yangtze River dolphin is a reminder of how vulnerable freshwater dolphins are.