Collaborative project: Offshore site selection for sustainable and multifunctional use of marine areas in heavily used oceans on the example of the North Sea

Objectives: The project aims to create a multi-use road map as a tool for the future use of marine areas in the German Bight. The combination of eco-friendly aquaculture with other infrastructures, such as offshore-wind farms as well as new strategies in the field of passive fisheries will be examined. This multiple use concept will help to regulate and reduce the impact on the ecosystem. Planned Tasks: Creation of a tool or model that will support the future planning and management of marine areas in the context of an aquaculture-wind farm combination. In addition, suitable test sites for multiple uses will be identified. These potential co-use-areas will be defined by using GIS decision tools, which are based on verified site-selection criteria. As a result, this analysis aims to obtain a review, adjustment and/or amendment of the “Marine Facilities Ordinance” as well as further required investigation (Environmental Impact Assessment, Licensing Procedure for Offshore Wind Farms I, II & III) to simplify the multiple-use of marine areas. AWI will check and establish the major site-selection criteria by combining data from medium-scale experiments with potential candidate species for offshore aquaculture as well as from computer-based models. Experiments in the AWI recirculation aquaculture system (RAS) investigate on nutrient fluxes within an integrated multi-trophic aquaculture (IMTA)-system. Model organisms are fish (turbot Scophthalmus maximus, sea bass Dicentrarchus labrax) as fed aquaculture candidates, bivalves (mussels Mytilus edulis, oysters Crassostrea gigas) and macroalgae (dulse Palmaria palmata) as extractive candidates. Nutrient fluxes between organisms will be analyzed and data will be used for the calculation of dimensions of future offshore-aquaculture-IMTA-systems. The IMTA concept enables the reduction of nutrient input by higher-trophic organisms (e.g. fish feed and feces), reducing pollution and eutrophication of the surrounding ecosystem. Lower-trophic organisms, such as bivalves and macroalgae, take up excess nutrients from the fish culture. Beside the valuable fish products, harvests of the lower-trophic species will achieve an additional economic benefit.