Reducing bycatch in beam trawls with (electrified) benthos release panels

Maarten Soetaert (Spreker op uitnodiging)

    Activiteit: Gesprek of presentatieLezing en mondelinge bijdrage

    Beschrijving

    Benthos release panels (BRPs) are known for their capacity to release large amounts of unwanted benthos and debris. Additionally, they are also more selective hence catching less undersized fish. However, until now, unacceptable commercial losses of sole (Solea solea L.) was hampering a successful introduction in commercial beam-trawl fisheries. To eliminate this drawbacks, two approaches were tested. First, the BRP was rigged differently to prevent slack. Second, the minimal electrical stimulus to immobilize Dover sole was determined in the lab with the idea of preventing the fish to dive and escape through the panel. Afterwards, a pulse module was developed to generate a small electric field in the aft end of the net above the BRP and the effect on the selectivity of square meshed with different mesh sizes (200, and 240mm) was determined. Our results indicate that a better rigging as well as electrifying the BRP allows to prevent sole from escaping. On one hand, the escapement of sole could be reduced with 10-20% by keeping the BRP stretched, which shows that a conventional BRP merits renewed attention. On the other hand, elaborate trials with an electrified 200 mm electrified BRP (eBRP) proved that this eBRP can release 20-50% of the benthos and debris caught without losing commercial sized sole. Additionally, also the bycatch of undersized fish of several species was reduced by this new development, which illustrates the promising potential of electric stimulation in the net to promote selectivity.

    Periode24-sep-201827-sep-2018
    EvenementstitelICES Annual Science Conference 2018
    EvenementstypeCongres
    LocatieHamburg, Duitsland
    Mate van erkenningInternationaal