Northern Europe's suitability for offshore European flat oyster (Ostrea edulis) habitat restoration: A mechanistic niche modelling approach

After centuries of overexploitation, European flat oyster (Ostrea edulis) habitats are increasingly being protected and large-scale oyster habitat restoration projects have been initiated in the North Sea, the English Channel, the Irish Sea and the north-eastern Atlantic.Understanding the habitat requirements of flat oysters is key in the selection process of restoration sites.In this study, a theoretical niche for all life stages of the flat oyster is determined using a dynamic energy budget model forced with temperature, chlorophyll a and salinity in combination with sediment composition. The suitability of Northern Europe's marine environment for flat oysters is evaluated by applying the proposed niche model on a spatial scale and evaluating spatio-temporal variability in life history traits and metabolic characteristics, such as fitness, reproductive output, settlement success and growth.Results show that habitat suitability is limited by low maximum summer temperature and low food availability at higher latitudes and in areas under strong influence of the Atlantic Ocean. Restoration efforts in Ireland and Scotland should be confined to protected and shallow coastal environments. Suitability in the southern North Sea is patchy and mainly depends on seabed substrate. The nearshore areas of the English Channel are highly suitable.The georeferenced dataset shared in this study will be useful for restoration practitioners.