Incidental Catches Of Marine Mammals In Fisheries In Sabah And Sarawak Waters, East Malaysia

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The nature and magnitude of incidental catches of marine mammals in fisheries was investigated in Sabah and Sarawak waters, East Malaysia, using a combination of interview survey procedures and observer trips on fishing boats. Between March 1997 and December 2004, we interviewed fishermen working on 753 and 358 boats in Sabah and Sarawak, respectively, who were employing trawl nets, purse seines, gillnets and fish stakes (kelong). They were asked questions about sightings of marine mammals and interactions with fishing. We also followed 36 trawl and 10 purse seine fishing trips in Sabah between June 2003 and December 2004. Fishing was conducted in coastal waters and the methods were briefly described and total annual catches by each method and region were estimated. Marine mammals were reported incidentally caught by 310 (41%) and 99 (28%) fishing boats in Sabah and Sarawak, respectively. Gillnetters, trawlers and fish stakes were reported to catch cetaceans and dugongs, while purse seiners caught only cetaceans. In certain areas, some caught animals were consumed, traded and/or used as shark bait. Overall, the magnitude of incidental catches of marine mammals is significantly greater in gillnets, as compared to other fishing gears. No catches were seen during observer trips. A total of 306 (95% CI = 250 – 369) cetaceans and 479 (95% CI = 434 – 528) dugongs were estimated to be caught annually by fishing fleets in Sabah. The Sarawak fishing fleet is estimated to incidentally catch 221 (95% CI = 189 – 258) cetaceans and 14 (95% CI = 2 – 30) dugongs per year. The estimated number of by-catches, particularly in gillnets, may be unsustainably high. A monitoring and educational program, together with the establishment of MPAs, is paramount to minimise the threat.