Onderzoek naar de verbetering van tongvangsten in de outrigvisserij

De laatste jaren is de boomkorvisserij onder druk komen te staan vanwege de effecten van deze methode van vissen op het mariene ecosysteem. De recente stijging van gasolieprijzen en daarmee samenhangende brandstofkosten van rond de 0.20 €/ltr tot ca. 0.70 €/ltr brengen de rendabiliteit van deze visserijsector in gevaar. Er wordt dan ook betwijfelt of de huidige boomkorvisserij nog toekomst heeft . Om deze redenen zoeken vissers naar alternatieve vangstmethoden, zoals de ‘outrig’ visserij. Deze methode, waarbij met een bordentrawl vanuit de gieken van een boomkorschip wordt gevist levert een aanzienlijke brandstofbesparing op, maar de vangst van tong is doorgaans minder door geringer bodemcontact

A compilation of length and species selectivity improving alterations to beam trawls

The increasing concern about the ecosystem effects of fishing on the marine environment and particularly, the impact of trawling on benthic communities is reflected in numerous publications. The weight of this concern will very likely only increase in management decisions in the near future. Beam trawling has a negative reputation with regard to discarding and seafloor impact and may be confronted with further constraints imposed by the fisheries management. The fishing industry has, however, the opportunity to anticipate management decisions and to adopt improved fishing gears, i.e. with reduced discarding and reduced environmental impact. A pro-active attitude and a voluntary uptake of improved gears allows the industry to shape the alterations to the specific conditions of the fishery and the fishing grounds. For the chain matrix beam trawl, many studies have been carried out on a wide variety of technical alterations to the beam trawl to improve the length and species selectivity, to reduce ecosystem effects and to reduce fuel consumption. The ILVO-Fishery institute has carried out many of these experiments and has recently been testing and promoting a combination of successful alterations. The improved trawl has been called the “alternative beam trawl” and has already been commercially tested for two years on a beam trawler. It consists of a number of simple and cheap alterations to the beam trawl. This report is a compilation of the most successful technical alterations for the beam trawl. The alternative beam trawl is not strictly defined and can consist of any combination of selective devices presented in this report or even new devices that prove to be successful. The basic idea is that each device that has undergone scientific scrutiny can be further developed by the industry in close cooperation with the fishery institute