Breakthrough Trawl Net Design26 May 2011
AUSTRALIA – The South Australian Reseach and Development Institute (SARDI) has revolutionised its trawl net design for South Australian (SA) prawn fisheries.The new design is comprised of larger holes which allow for small prawns and small fish to escape. The holes of the traditional diamond shaped net narrow during trawling which made it more difficult for small fish and small prawns to escape, meaning a large by- catch.
Leader of the two year SARDI project, Dr Shane Roberts, tested the new design with prawn fishermen in the Gulf St Vincent Fishery earlier this year and commented that the prawn fishers were thrilled with the new design as it improved the volume of their catches and benefited the environment.
“The fishermen are enthusiastic about it because not only is the new net achieving reductions in catches of both small fish and small prawns by up to 50 per cent, it retains larger prawns better, and allows greater water flow through the nets allowing them to be towed more efficiently, ultimately resulting in fuel savings”, he said.
The new net design, T90, was inspired by commercial fisherman Jim Raptis, who had been using a similar design for fish trawling in the Australian Bight.
Constructively, the new net features mesh oriented at 90 degrees to the body of the net and a different knot with thicker twine.
Dr Roberts also added that future research was moving towards a mega-fauna escape grid which aims to reduce the capture of stingrays, sharks and sponges. “Field tests are now underway and we will be refining its design and incorporating it with the T90 design over the coming year”, he said.
Over the past decade, the SA prawn industry has been working towards achieving better ecological sustainability and the introduction of the T90 nets is now another step closer to more sustainable fisheries in SA.
TheFishSite News Desk