Internal injuries in marine fishes caught in beam trawls using electrical versus mechanical stimulations

To improve the ecological and economic sustainability in the Dutch beam trawl fishery, tickler chains were replaced by electrical pulse stimulation to drive sole (Solea solea) out of the seabed. Because electrical stimulation may cause internal injuries, we quantified this risk by sampling fish species from commercial beam trawlers and recording spinal injuries and haemorrhages from X-radiographs and autopsy. To distinguish mechanically and electrical-pulse-induced injuries, we compared injuries in ten species sampled from pulse (PUL) and tickler-chain (TCK) trawlers and four species sampled from PUL trawlers with the stimulus switched on or off. Co-occurrence of a major spinal injury and major haemorrhage at the same location was only observed in PUL samples, and were frequently (40%) observed in cod (Gadus morhua) and in low numbers (0–2%) in whiting (Merlangius merlangus), grey gurnard (Eutrigla gurnardus), and greater sandeel (Hyperoplus lanceolatus), but not in flatfishes and other species. In cod, injury occurrence correlated with fish length, with lower probabilities for small fish. Major spinal injury or major haemorrhage occurrence in PUL (range: <1–16%) was lower than in TCK (range: <1–42%) in eight of the ten species studied. Population-level consequences of pulse-induced injuries are considered negligible.

Methods
See the manuscript mentioned at the end of this section for details on the creation of this data set. Description of column headers is provided in a separate data sheet: see "Usage notes".

Boute, P.G., Rijnsdorp, A.D., van Leeuwen, J.L., Pieters, R.P.M., Lankheet, M.J. (2023). Internal injuries in marine fishes caught in beam trawls using electrical versus mechanical stimulations. ICES Journal of Marine Science. DOI: 10.1093/icesjms/fsad064.