Funding: BMBF - Federal Ministry of Education and Research

Project period: 2023 - 2026

Cooperations:

Prof. Klaus Jürgens, Leibniz Institute for Balic Sea Research, Warnemünde, Germany

Prof. Michael E. Böttcher, Leibniz Institute for Balic Sea Research, Warnemünde, Germany

Prof. Andy Dale, Geomar Helmholtz Centre for Ocean Research, Kiel, Germany

The MGF-Baltic Sea project investigates the effects of mobile bottom-contact fishing (MGF), which is currently taking place on a large scale in the Baltic Sea and largely includes the Natura2000 protected areas within the German Exclusive Economic Zone (EEZ). The planned exclusion of fisheries in parts of the protected areas offers a unique opportunity to investigate the effects of fishing on benthic communities and sediment functions and to analyze their potential for regeneration. In the first phase of this project (MGF-Baltic Sea I), the current state of the benthic ecosystem was documented in the planned fisheries exclusion areas and in comparable reference areas outside the protected areas (but immediately adjacent). An important result of this baseline survey was that the intensity of MGF, documented by fishing effort data and drag marks in the sediment, was estimated to be comparably high in the reference and protected areas. Before fisheries are excluded, the baseline recordings for all protected areas should also be expanded and supplemented by seasonal aspects (example for a protected area). To investigate short-term effects of MGF (e.g. sediment resuspension) and to investigate various fishing gear, a trawl experiment is also carried out in a coastal area. The results will lead to a comprehensive assessment of the influence of MGF on benthic ecosystem functions as well as the development of indicators for MGF-related disturbances. Furthermore, the results will lead to concrete recommendations for action for fisheries management and future monitoring strategies in protected areas. The proposed sub-project investigates the effects of mobile bottom-contact fishing on microbial processes, in particular sulfate reduction, in the sediment. In addition, the recovery of the benthic ecosystems after the end of the disturbance by MGF will be investigated. In the context of this sub-project, mainly sulfate reduction rates are quantified using a radioisotope incubation method. In addition, dissolved substances in the pore water of the sediment are quantified to ensure direct comparability of the data with those of the other work packages.