Research Projects

Freshwater-dolphins in Bangladesh

Investigating the feasibility of using a passive acoustic method to estimate abundance and identify critical habitat of freshwater cetaceans in the Sundarbans mangrove forest, Bangladesh

Recent investigations conducted by the Wildlife Conservation Society's Asian Freshwater and Coastal Cetacean Program indicate that Bangladesh serves a regionally vital role as a reservoir of cetacean abundance and diversity – supporting several species that are known or believed to be at risk in other areas of their range. However, declines in population sizes are expected unless threats, particularly gillnet entanglement, are reduced.

The Bangladesh Cetacean Conservation Project is based on the strong potential to achieve effective conservation of several cetacean species at risk. A major research challenge of the project is to assess population sizes and identify the locations of high density cetacean occurrence for establishing a network of protected area. A particular emphasis is on threatened freshwater species - Ganges River and Irrawaddy dolphins.

Freshwater cetaceans possess highly evolved echolocation abilities that allow them to inhabit turbid environments where vision is of little use. Passive acoustic techniques take advantage of these vocalizations to detect and locate animals. Recently developed software algorithms have been used to determine bearings to dolphin clicks and whistles from a towed array. The aim of this project is to explore the potential of using an acoustic approach as an alternative, or adjunct, to visual survey methods normally used for assessing freshwater cetacean abundance and identifying their critical habitat. A team of acoustics experts and local scientists from Bangladesh will collaborate to assess feasibility, and, if it appears promising, devise a low-cost, user-friendly system to integrate into visual surveys.