TY - JOUR

T1 - Effects of bottom trawling and hypoxia on benthic invertebrate communities

AU - van Denderen, P Daniel

AU - Tornroos, Anna

AU - Sciberras, Marija

AU - Hinz, Hilmar

AU - Friedland, Rene

AU - Lasota, Rafal

AU - Mangano, Maria Cristina

AU - Robertson, Craig

AU - Valanko, Sebastian

AU - Hiddink, Jan Geert

PY - 2022/8/11

Y1 - 2022/8/11

N2 - Marine benthic habitats in continental shelf regions are increasingly impacted by hypoxia caused by the combination of eutrophication and climate warming. Many regions that have the potential for hypoxic conditions are being fished by mobile bottom-contacting fishing gears. The combined effects of trawling and hypoxia may be synergistic and disproportionally impact benthic fauna, or they may act antagonistically, leading to smaller trawl impacts in hypoxic areas. Yet, few studies have quantified how bottom trawling and hypoxia interact to affect benthic communities. Here we examine these combined effects on benthic community biomass and abundance, the number of large organisms, the longevity distribution of the community and the vertical position of fauna in the sediment in the southern Baltic Sea. We find large declines in benthic biomass and abundance that co-occur with declines in near-bed oxygen concentrations from 5.8 to 0.8 ml O2 l-1. Conversely, no relationships and weak positive relationships are found between bottom trawl disturbance and benthic community biomass and abundance. No interacting effects between hypoxia and trawling are detected. Our findings therefore highlight a low likelihood of synergistic impacts of bottom trawling and hypoxia on the benthic communities studied. These results suggest that management may prioritize benthic protection from fishing in regions that are not in a state of oxygen stress

AB - Marine benthic habitats in continental shelf regions are increasingly impacted by hypoxia caused by the combination of eutrophication and climate warming. Many regions that have the potential for hypoxic conditions are being fished by mobile bottom-contacting fishing gears. The combined effects of trawling and hypoxia may be synergistic and disproportionally impact benthic fauna, or they may act antagonistically, leading to smaller trawl impacts in hypoxic areas. Yet, few studies have quantified how bottom trawling and hypoxia interact to affect benthic communities. Here we examine these combined effects on benthic community biomass and abundance, the number of large organisms, the longevity distribution of the community and the vertical position of fauna in the sediment in the southern Baltic Sea. We find large declines in benthic biomass and abundance that co-occur with declines in near-bed oxygen concentrations from 5.8 to 0.8 ml O2 l-1. Conversely, no relationships and weak positive relationships are found between bottom trawl disturbance and benthic community biomass and abundance. No interacting effects between hypoxia and trawling are detected. Our findings therefore highlight a low likelihood of synergistic impacts of bottom trawling and hypoxia on the benthic communities studied. These results suggest that management may prioritize benthic protection from fishing in regions that are not in a state of oxygen stress

KW - Baltic Sea

KW - Body size

KW - Bottom-trawling

KW - Hypoxia

KW - Longevity

KW - Macrofauna

KW - Sediment

KW - Vertical position

U2 - 10.3354/meps14094

DO - 10.3354/meps14094

M3 - Article

VL - 694

SP - 13

EP - 27

JO - Marine Ecology Progress Series

JF - Marine Ecology Progress Series

SN - 0171-8630

ER -