Castnet Fishing with the Help of Irrawaddy Dolphin, Orcaella brevirostris, In Myanmar

Abstract

Fishing with the help of Irrawaddy dolphins is unique to Myanmar. Irrawaddy dolphins, Orcaella brevirostris, which live in about 74km segment of the Ayeyawady (previously known as Irrawaddy) in upper Myanmar help fishermen who use castnets for fishing. A total of 51 castnet fishermen from six villages can do fishing with the dolphins and about 21 dolphins in this river segment help the fishermen. Dolphins and fishermen communicate by audio and visual signals during the fishing. Fishermen can catch more fish with less fishing effort and dolphins can also feed easily on those fish which are stunned by the net throws. Irrawaddy dolphins have been protected by law in Myanmar since 1994. Nowadays, cooperative fishing practice between the Irrawaddy dolphins and castnet fishermen in Myanmar has been threatened with extinction by illegal electric fishing. It is an urgent need to study aquatic noise signals of dolphins, impacts of signals used by fishermen in communication with the dolphins and other noises such as boat noise on both dolphins and cooperative fishing practice.