Demersal fishery Impacts on Sedimentary Organic Matter (DISOM): a global harmonized database of studies assessing the impacts of demersal fisheries on sediment biogeochemistry

Marine sediments are among the largest carbon reservoirs on the planet and play a key role in the global cycling of organic matter. Bottom fisheries are the most widespread anthropogenic physical disturbance to seabed habitats, prompting NGOs and governments to act on regulating mobile bottom-contacting fishing gear. However, the scientific evidence of the effects of bottom trawling on sediment biogeochemistry is highly diverse and presents contrasting results. Here we present a global harmonized dataset of 71 independent studies that assess the effects of demersal fisheries on sedimentological (i.e. grain size, porosity) and biogeochemical (i.e. organic carbon, phytopigments, nutrient fluxes) properties: the Demersal fishery Impacts on Sedimentary Organic Matter (DISOM) database (Paradis, 2023; https://doi.org/10.3929/ethz-b-000634336). We identify considerable gaps, namely in the geographical extension of the data; coverage of environmental predictors (i.e. seasons); fishing descriptors such as the availability of true controls, quantification of fishing effort, and distribution of fishing gear types; and biogeochemical variables that study the remineralization of organic matter. Future studies should address these data gaps to enhance the comprehensiveness of the dataset. With this harmonized database, we aim to allow researchers to explore the effects of demersal fisheries in variable environmental settings to disentangle the effects of this disturbance and provide efficient management strategies.