Don't Let Go of the Long Line

     New South Wales Fisheries is a cooperating organization with the National Marine Science Center. At home the equivalent organization in the sense of research and management roles would be the Oregon Department of Fish and Wildlife. To gain further experience and expand my knowledge on the fisheries management in Australia, NSW Fisheries has allowed me to assist in their research. The project that I have been working on is a four year research project to reduce bytcatch in commercial fisheries. Bycatch refers to any part of the fishers catch that is not the target species. Current bycatch advancements thus far is largely the modification of the use of square mesh panels in codends. This utilizes the behavioural differences between prawns and fish to lessen the bycatch.  As the fish are herded together they try to escape by heading towards the top and sides of the codend and can escape through the open square-shaped meshes. By contrast, prawns have a limited reaction to the trawl and tumble along the bottom of the net into the codend.  The size of square-mesh used in the panel directly determines the size of fish that are allowed to escape. Studies in the oceanic prawn trawl fishery have shown that codends with relatively small panels of square-mesh were effective in removing up to 40% of the total unwanted bycatch (NSW Fisheries).  This sucess of the research thus far has led to further research on net placement and technique which is the current project I have the oppotunity to work on. NSW Fisheries cooperates with the local commercial fishermen, who allow us to attach devices to their nets that show the exact placement, depth, opening and movement of the nets and fuel usage while testing various net placements and set ups.  For each trawl we pull in the nets and sort the bycatch from the prawns being careful not to touch any of the poisonous fish, weigh the total bycatch and prawn weight, and take a sub sample in which we record size and species. Common bycatch found includes Mulloway, Bream, Ramseys perchlet, Sole, Flathead, Cat fish and Bullrout. The ultimate goal is to create a net design and placement combination that will further reduce bycatch and use less fuel without reducing yield (or reducing yield no more than the money they would be saving in lowering fuel expenses) thus an alternative that fishermen will actually implement because it does not detriment their profit will be created.