Cetacean Bycatch Risk in Gillnets and Trawls in Matang, Peninsular Malaysia
Sui Hyang Kuit & Louisa Shobhini Ponnampalam
Small cetaceans are particularly vulnerable to impacts from bycatch, yet baseline data on bycatch especially in developing countries are often mostly scarce. By integrating data from interviews and boat-based surveys conducted between 2013 and 2017, and using the Bycatch Risk Assessment (ByRA) toolkit, this study was to identify main bycatch gears and areas with highest bycatch risk of small cetaceans in Matang so as to guide planning for local bycatch mitigation strategies. A total of 198 respondents in 17 fishing villages in Matang were interviewed to assess fishersâ€™ perceptions, fishing effort, cetacean sightings and bycatch. The Indo-Pacific humpback dolphin was the most frequently reported cetacean species to be entangled by fishers. Gillnet, driftnet and trammel net were the main bycatch gears inshore that entangled humpback dolphins and Irrawaddy dolphins the most, whereas trawls were the more fatal bycatch gear offshore that entangled mostly Indo-Pacific finless porpoises. Kuala Sangga Besar and Kuala Larut were identified as areas with the highest cetacean bycatch risks. Bycatch mitigation trials such as the use of acoustic reflectors or pingers should be targeted on working with fishers using gillnets with mesh sizes of 1.5 to 4 inches that target threadfins, ariid catfishes, eel-catfishes, mullets, seabasses, and pomfrets off the two aforementioned areas for dolphin conservation. Exploration into the use of effective bycatch mitigation measures that do not greatly affect the fishersâ€™ catch would facilitate a wider adoption of those measures by more fishers to ensure better conservation success.