On the shelf of the Celtic Sea ecoregion there is as diverse groundfish community with over a hundred fish species regularly caught in trawl surveys. The most abundant demersal species are hake, haddock, whiting, and pout (Trisopterus spp). Common benthic and flatfish species in this ecoregion include anglerfish, dab, plaice, sole, lemon sole (Microstomus kitt), and megrim. Sprat (Sprattus sprattus), herring, and sandeels (Ammodytidae) are abundant inshore and on the shelf. Widely distributed pelagic fish species are more abundant along the shelf edge and include boarfish, blue whiting, herring, mackerel, and horse mackerel. Mueller's pearlside (Maurolicus muelleri), glacial lantern fish (Benthosema glaciale), and lancet fish (Alepisauridae) are the dominant mesopelagic species. These pelagic and mesopelagic species are important components of the foodweb in this ecoregion, and changes in their abundance can have significant consequences for this foodweb.
Relative spawning-stock biomass has increased since the late 1990s for many stocks, and the average biomass ratio is above MSY Btrigger for pelagic, demersal, benthic, and crustacean stocks (Figure 16). A number of stocks still have very low stock biomasses, namely cod and whiting to the west of Scotland, cod and whiting in the Irish Sea, and herring west of Scotland and in the Celtic Sea. The stock status of many elasmobranch species remains unknown.
Trends in fishing pressure are presented in the 'Selective extraction of species' section and in the Celtic Seas Fisheries Overview.
Figure 16: Time-series of annual biomass (SSB to MSY Btrigger ratio) by fisheries guild for benthic, crustacean, demersal, elamobranch, and pelagic stocks. Table A1 in Annex 1 details which species belong to each fish category.