Activiteit: Overige › Andere soorten (prijzen, externe en andere activiteiten) - (Co)promotor masterthesis
Shrimp trawling in the North Sea is criticized because of its high amount of by-catch and impact on the marine environment. An alternative fishing method with potential in reducing by-catch and seafloor contact has been developed over the last ten years. This study aims to evaluate the efficiency of the electrotrawl aboard the shrimp trawler HA 31 in the Wadden Sea by comparing the catches of an electrotrawl and a traditional trawl under commercial conditions over a fishing season (from June until December). Furthermore an attempt was made to find the optimal pulse intensity to be used in the electrotrawl. Also the influence of environmental variables on the catch composition was examined. Significant reductions were found for the undesired by-catch of both undersized shrimp and other marine species when fishing with the pulse trawl. This alternative fishing gear appeared to be effective in reducing the by-catch of especially juvenile fish without losing large amounts of commercial shrimp, compared to the traditional gear. An optimal pulse intensity was not detected, but a stagnation of the catch increase was observed with higher pulse intensity. The environmental variables showed strong correlations in between, whereby their effect on the efficiency of the pulse gear was unambiguous.