The main contributing activity to selective extraction of species in the Greater North Sea is fisheries. Sustainable fisheries management aims to minimize long-term negative effects on ecosystems while seeking long-term economic and social viability of the fisheries. Overall fishing effort in the Greater North Sea has fallen by approximately 50% (2004–2012). This decline in effort has resulted in a decline in the fishing mortality rate of commercial fish stocks. There have been shifts in fishing techniques. Beam trawling has been increasingly replaced by pulse beam trawling, sum-wing, twin-rigging, and flyshooting, gear types that all require less fuel. The impact of the EU landing obligation is difficult to predict, but fishing behaviour, data gathering, and stock assessments will be affected.
Figure 4: Effort trends for regulated gear types in a) Skagerrak/Kattegat, b) North Sea proper, and c) eastern English Channel. TR = demersal otter trawl and demersal seine, BT = beam trawl, GN = gillnet, GT = trammelnet, LL = longline. (STECF, 2013.)Impacts on commercial stocks
Figure 5: Time-series of annual relative fishing mortality (F to FMSY ratio) and biomass (SSB to BMSY trigger ratio) by fisheries guild for benthic, demersal, crustaceans, pelagic stocks. Table A1 in the Annex of the Ecosystem Overview document details which species belong to each fish category.