EU request on spatial trade-off analysis between reducing the extent of mobile bottom-contacting gear (MBCG) disturbance to seabed habitats and potential costs to fisheries

ICES advises that fishing with mobile bottom-contacting gears (MBCG) in EU marine waters of the Baltic Sea, Greater North Sea, Celtic Seas, and Bay of Biscay and the Iberian Coast areas is spatially aggregated into core areas that account for most of the total landings weight and landings value and peripheral areas accounting for a small proportion of total landings weight and landings value. On average, for the years 2017‒2022, and given the available data, ICES finds that 90% of MBCG landings value comes from less than 50% of the fished area when the percentages are evaluated at scale of c-squares (grid cells of 0.05° latitude × 0.05° longitude).

Core fishing grounds are defined as the smallest area yielding 90% of the landings value, evaluated annually at the c‑square scale. ICES advises that locations of core MBCG fishing grounds vary from year to year. For individual MBCG métiers, less than 50% of the c-squares fished at any time from 2017‒2022 were classified as core fishing grounds in every year in EU waters of the Greater North Sea, Celtic Seas, and Bay of Biscay and the Iberian Coast areas.

ICES conducted trade-off analyses to estimate the potential costs to MBCG fisheries in terms of reductions in MBCG fishing intensity, landings weight, and landings values to achieve a defined percentage of each Marine Strategy Framework Directive (MSFD) Broad Habitat Type (BHT) that is unfished (range of percentages 10‒90%, in increments of 10%).

For the Greater North Sea and the Celtic Seas areas, ICES advises that maintaining a persistently unfished state in 50% of the extent of all MSFD BHTs within the overall area is associated with an estimated reduction of 20% of the annual mean MBCG landings value. Maintaining 70% of BHTs in a persistently unfished state in the Greater North Sea and the Celtic Seas areas is associated with estimated reductions in landings values of 31.6% and 36.7% per year respectively. Results for individual subdivisions and BHTs are provided in this document and the accompanying interactive documents.

For the Baltic Sea area, ICES advises that maintaining a persistently unfished state in 70% of the extent of all BHTs within the overall area leads to an estimated reduction of less than 7% of the annual mean MBCG landings value. This is much lower than for the Greater North Sea and Celtic Seas areas, consistent with the absence of MBCG fishing in much of the Baltic Sea. For the Bay of Biscay and the Iberian Coast area, landings value reductions were not estimated because of data deficiencies.

Limitations apply to the input data, analyses, and advice. These include the omission of data for most < 12 m MBCG fishing vessels, the effects of analytical scale, the use of landings value rather than gross value added (GVA) as a measure of economic impact, not accounting for the ecological and fisheries consequences of displacement or landings value by displaced vessels, and incomplete vessel monitoring system (VMS) data submissions to ICES. The consequences of these limitations are elaborated in the ‘Limitations of the advice’ section.