Ecosystem overviews

Celtic Seas Ecosystem Overview

Pressure: Selective extraction of species

Selective extraction of species (including bycatch) is primarily attributable to commercial fisheries. Research cruises and recreational fisheries also operate in the region.

​​​Fourteen nations currently target stocks within the Celtic Seas ecoregion. Fishing activity, represented as port landings and effort, is spread widely around the coasts of the Celtic Sea ecoregion. The fleet varies in vessel size and time spent at sea, with busier ports indicated by larger circles in the figure. Analyses of the fishing activity in the ecoregion indicate that countries outside the ecoregion (i.e. those wihout a territorial border within the ecoregion) are responsible for 33% of effort allocated to the region and land around 43% by weight from the ecosystem, indicating the interconnected and interdependent nature of European fishing activity. Of the fish caught in the ecosystem, 47% was landed into ports in UK and Ireland, while 53% was landed elsewhere.

North Western Waters
(data based on North Western Waters region fleet which covers ICES areas 5, 6, and 7)

Both fishing effort and landings have generally decreased in the region since 2008. Total fisheries full‑time equivalent (FTE) employment in the North Western Waters (NWW) region decreased 6% from 12 315 in 2010 to 11 500 in 2018. Revenue (all income, including landings) generated by the fleets (based on available data) represented 21% of the total revenue for the EU fleet. The fleet operating in this region made EUR 309 million in gross profit in 2018; this represented a decrease of 18% compared to 2017 despite a generally increasing trend prior.

Based on value, the French, United Kingdom, and Irish fisheries have the largest landings in the North Western Waters region. Ireland has the highest total percentage of both national landed value (88%) and days-at-sea (98%), indicating its high dependency on this area. Belgium (43%), United Kingdom (60%), and France (29%) also have a high number of days‑at‑sea in the region. The fleet in this region consists of > 60% small scale fleet that account for 43% days at sea, provides job for around 22% of full-time equivalent employees and produced 14.2% of revenue. The rest of the fleet is represented by larger scale vessels that land around 93.5% of fish, or 86.6% of value. Total employment in NWW region in 2018 was estimated by STECF AER (Annual Economic Report) at 16 000 with the number of FTE employees at 11 500, an increase of 4% compared to 2017, but with a general decrease observed since 2008. The most important fleets in terms of overall employment correlate to those fisheries that have the highest dependency on this area (UK 4470 FTE, France 2837, Ireland 2465, and Spain 1245). Average wage per FTE for both the small and large scale fleet decreased in 2018 by 6% and 8% respectively (2017–2018). General trends indicate a slight downward trend for the small scale fleet and generally increasing wages for the large scale fleet (2008–2017).

​Recent socioeconomic issues

​COVID-19 pandemic

Responding to the rapid spread of COVID-19 and its variants, governments throughout Europe took the decision to enter successive lockdowns, with the subsequent collapse of the HOtel, REstaurant and Catering (HoReCa) and export markets. Ensuing seafood demand contraction and market uncertainty (price volatility), as well as temporary disruptions in fish auctions functioning and transport logistics (delays and higher costs), proved to be a sizeable challenge for the fishing sector.

Despite diversity in the severity and timing of impacts between regions, the value of landings (most notably for demersal and shellfish species) decreased more severely than their volumes (volume/value of landings: −10%/−26% for the Irish fleet,

 −10%/−20% for the UK demersal fleet, −4%/−13% for French fleet in the Celtic Sea). The most impacted fleet segments were those targeting high-value species and/or selling to the HoReCa sector. On the contrary, largely industrialized pelagic (mackerel [Scomber scombrus], herring [Clupea harengus] and blue whiting [Micromesistius poutassou]) and deep-sea fisheries in the Northeast Atlantic could rely on long-standing robust processing/retailing partnerships and as a consequence were not adversely impacted.

The long-term and multidimensional impacts on the seafood sector have yet to fully materialize.

​Withdrawal of United Kingdom from the European Union (Brexit)

As of 1 January 2021, UK became an independent coastal state with full responsibility over the waters of their EEZ, of which a significant portion is in the Celtic Seas ecoregion. Yet, under the United Nations Convention on the Law of the Sea, both UK and the EU have a duty to cooperate in the conservation and sustainable management of the ~100 stocks straddling their maritime boundaries, being further obliged to minimize economic dislocation for states whose nationals have habitually fished in the area.

Protracted and demanding Brexit negotiations have disrupted 2021 TAC-setting institutional processes until now, undermining the forecasting ability of both EU and UK seafood industries. While the Trade and Cooperation Agreement (TCA) guarantees full reciprocal access for a five-and-a-half-year period, it implies a significant quota transfer from the EU to the UK (by 2026 onwards, 25% of the value of pre-Brexit EU catches in the UK EEZ returns to UK). After the 1st of July 2026, access to waters will be decided in annual consultations. While the general framework of the new EU–UK relationship is established, practical implementation of the TCA remains a major challenge.

Although it is too early to appreciate the full extent of its consequences, Brexit is likely to impact the distribution of activity and profitability of EU fleet segments within the ecoregion during the upcoming years.

Ecological impacts of species extraction, including bycatch

Impact on commercial stocks

Overall fishing mortality (F) for shellfish, demersal, and pelagic fish stocks has reduced since the late 1990s (Figure 5), although the pelagic stocks are now above the reference point. Mean F is now closer to the level that produces maximum sustainable yield (MSY). The fishing mortality on 43 stocks has been evaluated (Figure 5) against MSY reference points; of these, 33 stocks are now fished at or below FMSY.

The Celtic Seas is the third most important area after the English Channel and North Sea for landings of loliginids (mainly the long‑finned squid [Loligo forbesii]). There was a substantial increase in landings of loliginids from the Celtic Seas in 2019. Cuttlefish (Sepia officinalis) are not as important in the Celtic Seas, but landings were up in 2019 on the previous year and approached levels last seen in 2015 (the second highest year in a series since 1992).

Detailed information on Celtic Seas fisheries is provided in ICES Celtic Seas ecoregion Fisheries ​Overview.

Bycatch and discards of commercial species

Total discard tonnage of pelagic species in the ecoregion is estimated to be very low. Discards of demersal, crustacean, and benthic species are estimated to be around 10%. Discard rates for some species are very high, for example plaice (Pleuronectes platessa [around 60% of tonnage]) and whiting (Merlangius merlangus [17–99% of tonnage]). The EU's landing obligation for demersal stocks came partially into force for its Member States in 2016 and has been in full force since 2019.

Impact on threatened and declining fish species

Several species have been depleted by fishing in the past and are now on the OSPAR list of threatened and declining species (see full in Table A2.1), including spurdog (Squalus acanthias), the common skate complex (Dipturus spp.), angel shark (Squatina squatina), porbeagle (Lamna nasus), and some deep-water sharks. High bycatch rates have recently been observed for some elasmobranch species which are of conservation concern in the Celtic Sea, particularly in trawl gears and nets. Although there are zero TACs, spatial restrictions, and prohibited listings for these species, several of them remain vulnerable to existing fisheries. Spurdog, thorny skate (Amblyraja radiata), thornback ray (Raja clavata) and the common skate complex currently experience high bycatch in mixed demersal trawl fisheries and gill and setnet fisheries, porbeagles and angel shark (less frequently) are taken as bycatch in some setnet fisheries, and deep-water sharks are caught in the mixed deep-water trawl fishery.

Impact on seabirds and marine mammals

Longline fisheries pose the greatest risk of bycatch to seabirds in offshore waters, while inshore net fisheries are known to catch diving bird species. Large-scale bycatch of great shearwaters (Puffinus gravis) has been reported from the hake (Merluccius merluccius) longline fishery on the Grand Sole fishing bank, and longline fisheries in waters north and west of Scotland appear to catch mainly northern fulmars (Fulmarus glacialis) and some other species at lower rates. Relatively high rates of common guillemot (Uria aalge) bycatch have also been observed in inshore net fisheries. Fisheries with risk of marine mammal bycatch in the Celtic Sea are bottom setnets (bycatch of harbour porpoises [Phocoena phocoena], grey seal [Halichoerus grypus], and several dolphin species but at lower rates) and pelagic trawls, particularly those for hake and previously seabass (Dicentrarchus labrax),  (bycatch of common dolphin Delphis delphinus). The mean annual bycatch of the common dolphin in 2016–2018 across all métiers ranged from 278–1345 individuals, with bottom otter trawls and gillnets targeting demersal fish accounting for the largest share. Modelling indicates that it is likely that the bycatch of harbour porpoises in gillnets on the Celtic Shelf has affected population abundance at least in some past periods. Calculations of potential biological removals (PBR) indicate that this bycatch may be unsustainable in this region. Recent estimates of grey seal bycatch in the region showed that percentage mortality of the grey seal population in the ecoregion was 1.5–2.8%. Given that the grey seal population in the area is steadily increasing, such bycatch rates are unlikely to have detrimental effects on the population. Bycatch in both fisheries may have been reduced in recent years due to lower fishing activity and the use of acoustic alarms attached to fishing gear as a mitigation technique in some parts of the fleet.

Ship strike has also been identified by the International Whaling Commission (IWC) as an issue for marine mammals. The Atlantic has been indicated as a potential hotspot for collisions, and incidents have increased in recent decades. However this may represent a reporting bias, and more data is required before drawing conclusions.

Recreational fishing

​Recreational fishing is an important activity in the Celtic Sea with a diverse range of species exploited from a variety of platforms (e.g. shore, boat) using many gears (e.g. rod and line, speargun, nets, pots, traps), along with hand collecting/harvesting from the shoreline. The main countries with recreational fisheries in the English Channel are UK, France, and Ireland, with methods varying between countries. In UK and France, no licence is required. In UK angling from shore and boat is the most popular method, with a number of charter boats offering trips. Angling, nets, and spearfishing are popular gears in France. Catches can be significant, representing around 5%, 27%, and 42% of total stock removals of cod (Gadus morhua), seabass, and pollack (Pollachius pollachius) respectively. The main targets include: saithe (Pollachius virens), cod, dogfish (Scyliorhinidae), flatfish (plaice, common dab [Limanda limanda], flounder [Platichthys flesus], and sole [Solea solea]), mackerel, pollack, sea bass, sea bream (Sparus aurata), wrasse (Labrus spp.), and whiting. There are also catches of sharks, skates, and rays. In addition, shellfish, crustaceans, and cephalopods are exploited.

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Figure 5: Time-series of annual relative fishing mortality (F to FMSY ratio) by fisheries guild for benthic, crustacean, demersal, and pelagic stocks. Table A1 in Annex 1 details which species belong to each fish category. ​

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Celtic Seas Ecosystem Overview

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