Effects of pulse on species
Studies on the effects of the electric pulse stimulation used in the fishery for sole on fish and invertebrate species are presented in ICES (2020) and Rijnsdorp et al. (2020) with the following conclusions:
- Exposure to a pulse stimulus does not lead to additional mortality but may lead to spinal injuries in fish. Extensive sampling of fish caught by commercial vessels showed spinal injuries in most of the fish species sampled from pulse trawls and tickler chain beam trawls.
- Pulse-induced spinal injuries are low (<1%) except in cod. Population level effects in cod are negligible for the North Sea stock and small for the southern North Sea stock because of the low exposure probability, and because the injury probability is lower in small cod.
- Electroreceptive fish like rays and sharks are not specifically sensitive to the high frequency pulses used in the sole fishery.
- It is highly unlikely that pulse trawling will compromise the reproductive capacity of the target species by non-lethal exposure to pulse stimuli.
- It is highly unlikely that a possible adverse effect of pulse exposure of eggs and larvae will lead to adverse population level effects
- The effects of pulse exposure in a sample of benthic invertebrate species representative for the fishing area of pulse trawlers was found to be non-lethal and temporary. Animals resumed their normal activity within an hour.
ICES. 2020. ICES Working Group on electrical trawling (WGELECTRA). ICES Scientific Reports, 2: 37. 115 pp.
Rijnsdorp AD, Boute P, Tiano J, Lankheet M, Soetaert K, Beier U, de Borger E, Hintzen NT, Molenaar P, Polet H, Poos JJ, Schram E, Soetaert M, van Overzee H, van de Wolfshaar K, van Kooten T. 2020. The implications of a transition from tickler chain beam trawl to electric pulse trawl on the sustainability and ecosystem effects of the fishery for North Sea sole: an impact assessment. Wageningen Marine Research report C037/18. 108 pp
Schram, E., and Molenaar, P. 2019. Direct mortality among demersal fish and benthic organisms in the wake of pulse trawling. Wageningen Marine Research Report C097/19. 42 pp