Accidental dolphin capture a difficult issue to solve April 3, 2014 Recently published research from Murdoch University scientists has revealed that around 500 dolphins have been caught in the Pilbara trawl fishery in the past decade. Bottlenose dolphins leaping alongside trawler. Photo: Simon Allen The research, by PhD candidate Simon Allen and colleagues from the Murdoch University Cetacean Research Unit, is based on independent observer data. “The data shows us that the methods and devices put in place in 2006 to reduce dolphin bycatch had an immediate effect but there has been no further reduction despite the industry’s best efforts,” Mr Allen said. “Independent observers reported bycatch rates of about 50 dolphins per year, which is double the number reported by the skippers of these vessels.” Mr Allen said under reporting is not unusual around the world, especially where marine mammal capture is illegal. “This doesn’t necessarily mean that skippers are deliberately under reporting. Fishers are concentrating on the job at hand and may not see a dead dolphin fall out of the net on winch up,” he said. A recent report by Western Australia’s Department of Fisheries detailed similar findings, but instead suggested that the self-reporting mechanisms in place were accurate and that the impact poses ‘negligible risk’. Co-investigator Professor Neil Loneragan said the paper makes a number of recommendations to better monitor and reduce bycatch. “The bycatch reduction devices had bottom opening escape hatches, with an unknown quantity of bycatch falling out and therefore not being reported,” he said. “Modified bycatch reduction devices with top-opening escape hatches may be more effective.” The scientists have also called for a reinstatement of independent observers, as well as in-net video collection so that bycatch can be accurately measured. “The next step is to calculate the acceptable levels of human-caused dolphin mortality, which requires an estimate of the dolphin population size in the region,” Mr Allen said. “If the ongoing bycatch exceeds that threshold, switching to alternative, less destructive fishing methods, like trap or line fishing, should be considered.” The paper has been published in open access journal PLOS ONE and is available here. Print This Post Media contact: Jane McNamara Tel: (08) 9360 2985 | Mobile: 0418 391 124 | Email: email@example.com Categories: General, Future Students, Research, School of Veterinary and Life Sciences, School of Veterinary and Life Sciences Research Tags: bottlenose dolphin, department of fisheries, murdoch university, murdoch university cetacean research unit, neil loneragan, pilbara, simon allen, trawl fishery We read every comment and will make every effort to approve each new comment within one working day. To ensure speedy posting, please keep your comments relevant to the topic of discussion, free of inappropriate language and in-line with the editorial integrity of this newsroom. If not, your comments may not be published. Thanks for commenting!