Combining (floating) offshore energy and nature-inclusive seafood production, with a focus on suspended mussel cultivation in the North Sea

Aquaculture of low-trophic species such as shellfish (mussels, oysters) is associated with several socio-economic and ecological benefits. However, the European shellfish farming sector, mostly carried out in coastal areas, has been stagnating over the past two decades, mostly due to spatial conflicts and environmental concerns. To overcome these challenges, a move towards offshore locations has been considered for several European basins. Besides offering better water quality and lower temperatures compared to near-shore sites, offshore high-energy hydrodynamics can mitigate the impact of organic pollution from farms. Additionally, previous offshore mussel farming pilots have demon-strated a positive impact on the surrounding ecosystem, including biodiversity enhancement and restorative effects on degraded seabeds. In Europe, the fast expansion of the offshore energy sector can provide large opportunities for the development of the shellfish farming industry within multi-use settings. This project will explore the environ-mental feasibility and restorative benefits of offshore suspended cultivation of the blue mussel Mytilus edulis in the southern North Sea. As part of the HybridLabs NWO project, focusing on the development of floating energy structures (solar panels, wind turbines) for offshore environments, this project will delve into the potential for integrating mussel cultivation with (floating) energy production. Over the course of four years, research will expand over four fields of impact: 1) M. edulis’ consump-tion of planktonic resources, with a focus on the under-studied pico- and nano-planktonic size classes, 2) the dispersion and ecological fate of the (pseudo)faeces released by mussels, 3) the potential for pelagic and 4) benthic biodiversity enhancement around and underneath the suspended mussel lines. Research efforts will comprise a combination of in-situ, mesocosm and laboratory-based studies. In collaboration with HybridLabs partners, novel (non-invasive) methodologies, including automated eDNA sampling and 360°C camera recordings, will be applied to monitor the farm’s impact and biodiversity developments around the study farm sites. Ultimately, this research aims to inform on the potential of offshore nature-inclusive mussel farming to represent a sustainable source of seafood alongside providing restorative benefits to the North Sea pelagic and benthic ecosystems.