Vulnerability of megabenthic species to trawling in the Barents Sea

The development of ecosystem-based fisheries management over the last two decades has increased attention on the protection of vulnerable resources that are of little or no economic significance including bycatch of benthos in bottom trawling. Current knowledge on the response of benthic communities to the impact of trawling is still rudimentary. In the present study, we used data collected in the Barents Sea during 2011 to assess the vulnerability of benthic species to trawling, based on the risk of being caught or damaged by a bottom trawl. Using trait table analysis, we identified 23 “high-risk” benthic species, which include “large weight and upraised” taxa as “easily caught” by a bottom trawl. We further identified a “low-risk” category containing 245 taxa/species and a “medium-risk” category with 80 species. A clear decline in biomass was noted for all three categories when comparing trawled vs. untrawled areas. This suggests that trawling significantly affects the biomass of all species, but predominantly the “high-risk” taxa. Some Barents Sea regions were particularly susceptible to trawling due to the dominance of the “high-risk” species, includingGeodia sponges in the southwestern Barents Sea, basket stars (Gorgonocephalus) in the northern Barents Sea, sea pen (Umbellula encrinus) on the shelf facing the Arctic Ocean, and sea cucumber (Cucumaria frondosa) in shallow southern areas. These findings can guidemanagementdecisions tomeet targets set by theUnitedNationsConventionof BiologicalDiversity and theOSPARCommission (“Protecting andConserving theNorth-EastAtlantic and its Resources”).We specifically recommendmanagement action in the southwestern and the northwestern Barents Sea and on the Arctic shelf facing the Arctic Ocean.