The Irrawaddy Dolphin is technically an oceanic species, living along the coasts of Asia. But the dolphins also live in three river systems — the Mekong, the Irrawaddy and the Mahakam. And these freshwater populations are under greater threat than the oceanic populations. While the International Union for Conservation of Nature lists the global Irrawaddy Dolphin population as “Endangered,” all three riverine subpopulations are “Critically Endangered.”
One of these, in the Mahakam River of Indonesian Borneo, is now home to only about 80 individual dolphins. Over the past few decades, habitat loss and unsustainable fishing have reduced the local population to near-extinction. That’s why Rainforest Trust began working with the local organization Yayasan Konservasi – Rare Aquatic Species of Indonesia (YK-RASI). Together, they planned to protect habitat in and along the Mahakam River to save this imperiled group of dolphins.
https://www.rainforesttrust.org/new-aquatic-nature-reserve-protects-critically-endangered-river-dolphins-in-borneo/