Effects on the ecosystem
Bottom trawls impact the structure and functioning of the benthic ecosystem (Jennings and Kaiser, 1998). The impact is related to the mechanical effects of the gear components that either sweep or penetrate into the seafloor (Eigaard et al. 2016). Bottom trawls may homogenise the texture of the seafloor, disturb the sorting of the sediments and bring sediment into resuspension in the wake of the gear (O’Neill et al., 2016). Mechanical disturbance will also kill benthic invertebrates and may destroy biogenic structures (Kaiser et al., 2006). In addition to the mechanical impact, electrical stimuli may affect the ecological functioning of the benthos and may influence chemistry of the seabed.
Hypothesis on chemical reactions
It is hypothesised that the electrical field may affect chemical reactions which might release pollutants that are bound to sediment particles (Soetaert et al., 2015). To our knowledge, no studies have addressed this question.
Unknown effects on functioning of benthic invertebrates
It is unknown how chronic sub-lethal exposure will affect the functioning of the benthic invertebrates. Although the few experiments with benthic invertebrates seems to suggest that the exposed organisms resumed their normal behaviour soon after the pulse treatment, further studies are required.
Documents
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Pulse fishing and its effects on the marine ecosystem and fisheries
This research project was carried out by Wageningen Marine Research at the request of and with funding from the Ministry of ...
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Measuring and assessing the physical impact of beam trawling
Research article published in ICES Journal of Marine Science. Authors: Jochen Depestele, Ana Ivanovic, Koen Degrendele, Moosa ...
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Effects of beam and pulse trawling on the benthic ecosystem
Here we study the effects of fishing trawl gear on the seabed and benthic organisms. A BACI-design experiment was used to examine ...