Preliminary Assessment of Cetacean Incidental Mortality in Artisanal Fisheries in Anakao, Southwestern Region of Madagascar

Abstract

Cetacean by-catch in artisanal fisheries in the southwestern region of Madagascar was  previously documented through surveys conducted in this region. To build on initial findings, a research project was conducted to further evaluate by-catch in this region. Interview surveys were conducted between October 2005 and January 2006 in four seaside villages to gather information on cetacean by-catch in artisanal fisheries. A total of 111 interviews were analyzed, resulting in an estimate in 56 by-catch events in the four villages between 2000 and 2005. These events involved in an estimate of 79 animals entangled in fishing gear, which we believe is an underestimate. Three dolphin species and humpback whales were reported accidentally caught in fishing gear meant to catch sharks. Dolphins were mostly reported as to be entangled in gillnets; conversely longlines were only described to incidentally catch humpback whales. Bottlenose and spinner dolphins were respectively 48.10% and 31.64% of total cetacean by-catch between 2000 and 2005. Improved fisheries management and effective cetacean population management are needed to mitigate threats to cetaceans from artisanal fisheries in the southwestern region.