Management of sustainable fisheries alongside marine renewables: modelling the spatial interactions

Extracting energy from waves and tides is seen as crucial to the achievement of ambitious national targets for meeting energy demands from renewable sources (e.g. 100% of electricity demand by 2020 in Scotland), but the requirements of this new industry must be balanced against the needs of traditional users of the sea, particularly marine fisheries. Whilst previous studies have indicated relatively little overlap between hydrodynamic energy resources and exploited marine fish stocks at national scales, there appears to be greater potential for locally-significant interactions involving inshore fisheries. Although interactions are expected to differ according to marine renewable energy development types and technologies, and to involve spatial scales ranging from devices and individual fish to regions and fish stocks, the first concern for fisheries is likely to centre on spatial occupancy of fishing areas by developments. Whilst exclusion from portions of traditional fishing grounds can be seen as a loss of fishing opportunity, it is also relevant to consider that spatial measures can be an important tool for fisheries management. We develop a spatial model of yield and spawning potential for inshore fisheries, demonstrating the sensitivity of sustainable management criteria to spatial exclusion of fisheries activities at scales relevant to marine renewable energy developments. We show that the sum effects of multiple exclusion zones depend on the interaction between spatial turnover of fish populations and the size and shape of these zones. Fish mobility is a primary factor in determining sensitivity to spatial management measures, but this factor is mediated by the ways in which patterns of individual movement and site fidelity determine spatial turnover at a population level. Managed sensitively with respect to potential impacts and opportunities, there appears to be considerable scope for positive working relationships between the marine renewable energy and fishing industries, but this depends to a large extent on the development of effective frameworks for marine spatial planning.