Short-term effects of Danish seining on seabed fauna in a shallow coastal ecosystem

Danish seining is a fishing method in which long ropes are hauled over the seabed from an anchored vessel. In Denmark, it has been used widely for catching plaice ( Pleuronectes platessa ). Despite its commercial use, empirical evidence on its effects on seabed communities remains limited compared with other bottom towed gears. This short communication presents results from a field experiment designed to assess the short-term effects of a Danish seine haul on benthic macrofauna in the southern Skagerrak. Benthic samples were collected immediately before and after fishing to detect potential changes in community characteristics. Minor declines in total abundance, biomass, and species richness were observed following seining, but none of these responses were statistically significant. Overall community composition also showed no significant changes. However, several species specific responses were observed. The annelids Owenia fusiformis and Magelona mirabilis increased in abundance, whereas the phoronid worm Phoronis muelleri , the bivalve Chamelea gallina , and brittle star Ophiura ophiura declined. The sensitivity of Phoronis muelleri , a soft bodied tube-builder, has been noted in other trawling impact studies and likely relates to its protruding position above the sediment surface, making it potentially vulnerable to the large seabed footprint of the seine ropes. Overall, our findings show that a Danish seine haul in shallow coastal habitats causes relatively minor short-term disturbances to the benthic fauna, and thus, exhibit reduced ecological impacts on the seabed than other commercial bottom trawling gears, such as otter and beam trawls. • Experimental trial assessing benthic impacts of Danish seining. • Community abundance, richness and biomass showed no significant change. • Species specific responses observed, with declines in some sensitive taxa. • Results suggest Danish seining has lower impact than conventional bottom trawls.