Shifting baselines in European fisheries: The case of the Celtic Sea and Bay of Biscay

Abstract

Stocks status and ecosystem indicators of the Celtic Sea and the Bay of Biscay were analysed from 1950 to 2008 based on landings, stocks assessments data and additional auxiliary observations. The apparent stability in landings over the last 50 years masks the fact that the fisheries have been sustained at the cost of a dramatic increase in fishing pressure, and a change in species composition and fishing grounds. Major changes occurred between 1950 and 1970s with a major decrease in the global biomass index. The mean asymptotic length of fish landed has declined by 32 cm (19 cm for demersal fish alone) and the mean trophic level by 0.25. Both the Primary Production Required by the fishery and the Fishing in balance index have declined since the 1980s. All indices lead to conclude to a pervasive overexploitation over the last 30 years. Most exploited species considered are characterized by a severe truncation of their length and age structures, the reliance of the fishery on new recruits, and a large proportion of immature individuals in the landings. For most assessed stocks, fishing mortality is higher than Fmax and close to Fpa. Rebuilding the stocks will require a 2–3-fold decrease in fishing mortality.