The bulk of the fisheries in the region, both pelagic and demersal, occurs at depths of less than 500m. There has been an overall reduction since 2005 in fishing effort for fisheries using trawl, longline, gillnet, seine and Danish seine, but an increase in the effort for pelagic trawl and jiggers (figure 4).
Egg collection and hunting of seabirds takes place mainly in the northwestern and southern parts of Iceland. These activities have decreased to very low levels compared to the period 1900–1940. The culling of seals, introduced in the early 1980s to reduce infestation of seal worm in demersal fish, ended for harbour seals Phoca vitulina in the 1990s and for grey seals Halichoerus grypus in the early 2000s. This resulted in a decline in the seal populations, with no increase in abundance in recent years. Commercial whaling started again in 2006 with an annual TAC of 154 fin whales and 229 minke whales. No fin whales have been caught since 2015, and annual catches of minke whales have varied from 25 to 81 animals since 2006.
The majority of the fishery in the Icelandic Waters ecoregion is performed by Icelandic vessels, with only a small proportion of the catch taken by others through Iceland's bilateral agreements with neighbouring countries.
The gadoid stocks, along with several others, are assessed by analytical methods, whereas assessments of flatfish species are mainly based on survey indices and landings. For stocks with an analytical assessment and defined reference points, the exploitation rate (fishing mortality [F] and/or harvest rate [HR]) has declined in recent years and is now at FMSY or HRMSY (figure 5), and the spawning-stock biomass is in all cases above Btrigger (figure 10).
In general, the trends in HRproxy (catch/survey biomass) for gadoids and for 'other species' (redfish, tusk, ling, and wolffish Anarhichas lupus) show the same trend as in Figure 5, i.e. the HRproxy is currently at a low value (figure 6). For the flatfish species the HRproxy has fallen drastically from the period 1995 to 2000, mainly owing to the directed commercial fishery for dab and long rough dab Hippoglossoides platessoides having largely ceased.
The pelagic fish stocks are also assessed by analytical methods, except for capelin which is assessed and managed on the basis of acoustic measurements and escapement strategy. The fishing trends for the highly migratory stocks, mackerel, blue whiting Micromesistius poutassou, and Norwegian spring-spawning herring, are presented in the ecosystem overview for the Norwegian Sea ecoregion.
A few species have been critically impacted by fishery in the ecoregion. One of these species is Atlantic halibut Hippoglossus hippoglossus. The biomass survey index for Atlantic halibut decreased between 1985 and 1995 and has since then remained at a low levels, with a small increase observed in 2015 and 2016. Additional management measures, a mandatory release of viable halibut and a landings ban, were introduced in 2012.
Several of the species listed on the OSPAR list of threatened and declining species are known bycatch species in the Icelandic fishery. However, landings are in general small or incidental and little is known about the impact of fishery on these species.
Bycatch of seabirds, small cetaceans, and seals is known to occur in bottom setnets, particularly in Breidafjordur (western Iceland) and in the north. Harbour porpoise Phocoena phocoena is the most commonly bycaught marine mammal, but seals are also caught, especially in the lumpsucker Cyclopterus lumpus fishery.
The main bycaught seabird species are northern fulmar Fulmarus glacialis , common murre Uria aalge, northern gannet Sula bassana , black guillemot Cepphus grille, and common eider Somateria mollissima, all caught in bottom setnets. Bycatches in gillnets targeting cod have decreased, associated with a large decrease in effort. The annual estimate of bycatch of harbour porpoise has also decreased, from 7300 animals in 2003 to 900 in 2015. Data from the most recent (2007) aerial survey of Icelandic coastal waters show that the estimated incidental captures of harbour porpoise in 2015 comprise 0.53% of the estimated abundance.
Figure 4: Temporal
trends in effort by gear since 1992, based on logbook entries.
Figure 5: Relative fishing mortality (F to FMSY or HR to HRMSY ratios) for cod, haddock, saithe, herring, ling, golden redfish (Sebastes norvegicus), tusk, and Atlantic wolffish. The dotted line denotes FMSY / HRMSY.
Figure 6: Trends in HRproxy (catch/survey biomass) for plaice Pleuronectes platessa, lemon sole Microstomus kitt, witch, dab, cod, haddock, saithe, golden redfish, Atlantic wolffish, ling, and tusk. Please note that the average line (dashed) is standardized relative to its lowest value.
Figure 10: Relative
spawning-stock biomass (SSB
to Btrigger ratios) for cod, haddock, saithe, golden redfish, and herring.
The dotted line denotes Btrigger.