First Interim Report of the Working Group on Electrical Trawling (WGELECTRA)
The Working Group on Electrical Trawling (WGELECTRA) met in Ostend, Belgium from 21–23 October 2014 to review knowledge of the effects of electrical fishing on the marine environment, (a) evaluate the effect of a wide introduction of electric fishing; (b) conduct a pilot study on control and enforcement procedures for flatfish pulse trawling; (c) evaluate the impacts of restrictions on pulse characteristics for shrimp pulse trawling and groundrope configurations; (d) and to make an inventory of views on pulse fishing among various stake-holders in European member states. The major findings were as follows.
The pulse stimulation tested in a uniform field did not result in an increased mortality or macroscopic lesions in sole, cod, brown shrimp and rag-worm. No mortality or ёspinal injury, but minor haemorrhages and point bleedings were found in plaice, sole, cod, armed bullhead, and bull-rout. Some effect was found on egg stages of sole, but no real effect on larval stages. Lesions were found in dab under pulse stimulation, but no clear differences between treated fish and reference fish could be distinguished. The results of tank tests on cod under pulse stimulation varied considerably, which was attributed to differences in rearing of the fish. A catch comparison between a new shrimp pulse trawl (12 electrodes and 11 bobbins) and a conventional shrimp trawl (36 bobbins) showed that shrimp landings remained the same, with less undersized shrimp and much less bycatch. Electrofishing on razor clam in Scottish waters has minimal effect on the seabed compared with conventional dredge and trawl fisheries; immediate effects on non-target species are non-lethal and effects on invertebrate behaviour are short term, but restrictions on fishing effort may be needed in view of high efficiency of electrofishing. A yearlong study in Germany showed that bycatch of non-target species can be reduced by electrical stimulation in shrimp trawling. The specifications of the groundrope arrangement (number and size of bobbins) need careful consideration too. New developments might be a twin-rig using pulse stimulation for catching plaice and sole, and the use of electrical stimulation at the position of escape windows. The group recommends meeting again next year to discuss the ToRs.
Published under the auspices of the following ICES Steering Group or Committee
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