Final report to the New England Aquarium on pinger displacement trials for Ganges River dolphins Platanista gangetica in the Sundarbans mangrove forest, Bangledesh

Smith, B.D.
Journal/Publisher Name
Wildlife Conservation Society
Page #s

A study was conducted in Sundarbans mangrove forest of Bangladesh to assess the behavioral response of Ganges River dolphins to pingers. Just under 62 hours of theodolite tracking data from 75 dolphin sightings and 2,829 theodolite fixes of dolphin surfacing were analyzed. The results suggest pingers had a subtle displacement effect on the dolphins. There was an increase in the mean surfacing distance of dolphins from the pinger buoy within a 100 m radius. Pingers did not result in a decrease in the minimum distance of approach for dolphins. Pingers did not change the frequency of sightings detected within 100 m of the pinger buoys. The results remain unclear whether pingers would be able to prevent entanglement in gillnets by Ganges River dolphins.