DOI: https://doi.org/10.3354/meps14094
copiedEffects of bottom trawling and hypoxia on benthic invertebrate communities
- P. Daniël van Denderen
- Anna Törnroos
- Marija Sciberras
- Hilmar Hinz
- René Friedland
- Rafal Lasota
- Maria Cristina Mangano
- Craig Robertson
- Sebastian Valanko
- Jan Geert Hiddink
ABSTRACT: 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.
KEYWORDS
P. Daniël van Denderen (Corresponding Author)
- Centre for Ocean Life, DTU Aqua, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI 02882, USA
Anna Törnroos (Co-author)
- Environmental and Marine Biology, Faculty of Science and Engineering, The Sea research profile, Åbo Akademi University, 20520 Turku, Finland
Marija Sciberras (Co-author)
- The Lyell Centre, Heriot-Watt University, Edinburgh, EH14 4AP, UK
Hilmar Hinz (Co-author)
- Mediterranean Institute for Advanced Studies, IMEDEA (CSIC-UIB), Marine Ecosystem Dynamics, 07190 Esporles, Balearic Islands, Spain
René Friedland (Co-author)
- Leibniz-Institute for Baltic Sea Research Warnemünde, 18119 Rostock, Germany
Rafal Lasota (Co-author)
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Ecosystems Functioning, 81-378 Gdynia, Poland
Maria Cristina Mangano (Co-author)
- Department of Integrative Marine Ecology (EMI), Stazione Zoologica Anton Dohrn, Sicily, 98167 Messina, Italy
Craig Robertson (Co-author)
- Bangor University, School of Ocean Sciences, Menai Bridge, LL59 5AB, UK
Sebastian Valanko (Co-author)
- International Council for the Exploration of the Sea, Copenhagen, 1553, Denmark
Jan Geert Hiddink (Co-author)
- Bangor University, School of Ocean Sciences, Menai Bridge, LL59 5AB, UK
