WP 3.2 Benthic fluxes

Mobile bottom-contact fishing causes sediment resuspension, changing sediment structure and destroying communities of macrobenthos in and on the sediment, ultimately contributing to the poor ecological status of parts of the seabed in the North Sea. In a first phase, the current biogeochemical state of the marine protected areas "Sylter Outer Reef", "Borkum Reef Ground" and "Doggerbank" of the German Exclusive Economic Zone is  captured. In order to evaluate an exclusion of mobile bottom-contact fishing in these marine protected areas, sediment characteristics are determined and specific benthic respiration- and remineralization rates are measured with flow through reactors, at stations with and without fishing pressure. The gained results towards sediment characteristics and respiration- and remineralization rates are going to be used, to model benthic fluxes of nutrients and oxygen. Furthermore, the effects of a fishing exclusion on the prevailing benthic communities are going to be investigated. The aim of WP 3.2 is to quantify current turnover rates, in order to evaluate the impact of a fishing exclusion. We expect benthic communities to recover without disturbance, so that a regeneration of the ecological structure and function may take place. Furthermore, we expect the sediments to better restrain suspended matter.