Bass, seabass (Caught at sea)
Capture method — Demersal otter trawl
Capture area — North East Atlantic (FAO 27)
Stock area — Central and southern North Sea, Irish Sea, English Channel, Bristol Channel, Celtic Sea
Stock detail — 4b, 4c, 7a, 7d-h
Updated: July 2019.
Bass is important to inshore artisanal fishers, offshore fisheries, and recreational anglers, and has a high socio-economic value. Historically, commercial seabass landings were minimal and the species was mainly the quarry of recreational anglers, but since the 1970s the commercial catch has escalated and by mid 1990s was believed to equal the recreational take. The combination of slow growth, late maturity, spawning aggregation, and strong summer site fidelity increase the vulnerability of seabass to over-exploitation and localised depletion.
Spawning stock biomass (SSB) for this stock has been declining since 2005 and is now only slightly above Blim (if the stock size falls below Blim, its ability to reproduce may be impaired). The stock is not, however, being subjected to overfishing, as fishing pressure has been successfully reduced by a series of management measures. An error was found in ICES’ July 2018 assessment, the correction of which resulted in a revision of estimates of recreational catch and an update to the reference points for this stock. Total removals by commercial and recreational fisheries are not well documented, and are consistently higher than is advised. Discards are poorly understood, but are known to consist of young fish. Better selectivity and spatial management measures are needed to address this. Demersal otter trawls take about 14% of the catch. Most bass in trawl fisheries is bycatch. Trawling can damage the seabed and bycatch vulnerable species: bycatches of skates, rays and sharks (elasmobranchs) take place in most European otter trawl fisheries.
Bass or seabass belongs to a family of spiny-finned fish called Moronidae, which are closely related to groupers. Bass breed from March to mid-June, mostly in April, in British coastal and offshore waters, from January to March in the Bay of Biscay and from February to May in the English Channel and eastern Celtic Sea. It is a long-lived and slow growing species - up to 30 years of age - and can achieve a length of up to 1m with a weight of 12kg. Male bass mature at 31-35cm (aged 3-6 years) and females mature at 40-45cm (aged 5-8 years). Once mature, bass may migrate within UK coastal waters and occasionally further offshore. Increases in sea water temperature in recent decades has likely led to a more northerly distribution of seabass, as it is now found further north into the North Sea. Climate warming may also have lengthened the time adult seabass spend in the summer feeding areas. After spawning, seabass tend to return to the same coastal sites each year.
Criterion score: 0.5 info
Central and southern North Sea, Irish Sea, English Channel, Bristol Channel, Celtic Sea
The stock is at a very low size, but fishing pressure is within sustainable limits. The assessment has been revised and reference points have been updated, but the main changes to advice result from above-average recruitment in 2013 and 2014, low fishing mortality, and increase in stock size.
Spawning-stock biomass (SSB) has been declining since 2009 and in 2018 it was 10,313 tonnes, below MSY Btrigger (14,439 tonnes) and equivalent to Blim (10,313t). In 2019 it has increased to 10,884t. Fishing mortality (F) has increased over the time-series, peaking in 2013 at 0.27 before a rapid decline to 0.079 in 2018 - below FMSY (0.17). Recent recruitment is low, fluctuating without trend since 2008. The combination of increasing fishing mortality, and environmental conditions causing poor recruitment since 2008, appears responsible for the continuous decline in biomass.
ICES advises that when the EU multiannual plan (MAP) for Western Waters and adjacent waters is applied, total removals (commercial and recreational) in 2020 that correspond to the F ranges in the MAP are between 1634 tonnes and 1946 tonnes. This is a 7.8% increase on 2019 advice, which in turn was a 105% increase on the 2018 advice. The upper limit of the range for 2020 equates to a fishing mortality of 0.135 - below FMSY but also leading to a projected 4.8% decrease in SSB (taking it to 10,861t).
An error was found in the July 2018 assessment, the correction of which resulted in a revision in estimates of recreational catch. This has led to a downward revision in SSB at the beginning of the series, as well as an upward revision of SSB and a downward revision of F in recent years. Reference points were updated accordingly in this (July 2019) assessment. The new reference points now indicate that while the stock declined to Blim in 2018, it has never actually fallen below Blim.
Poor catch data quality, owing to limited sampling of the discards and recreational removals, leads to additional uncertainty in the assessment. Stock identity remains poorly understood; tagging and genetic studies are taking place to address this.
Criterion score: 0.75 info
A series of emergency management measures were brought in in 2015, and have been developed and added to since. These seem to have effectively reduced overall fishing mortality so that the stock is no longer subject to overfishing. However, recreational catches are not properly understood or accounted for, and discarding is significantly underestimated. More needs to be done to reduce catches of undersize fish through better selectivity and spatial management measures. There is evidence that illegal targeting of seabass is taking place: if this continues, it could jeopardise the status of the fishery. Sea bass recruitment is sensitive to environmental pressures, but because of the low stock size there is a risk that recruitment would be impaired even under beneficial environmental conditions.
This stock is now covered by the EU Western Waters Multi Annual management Plan (MAP), which contains ranges for target fishing pressure. Taking only commercial landings and discards into account, catches were nearly double the advice in 2015 and 2016. The 2017 advice was for 0 catch and 2018 advice was for 880t but total commercial catch in both years was over 1,200t. When taking recreational catches into account, total catches are even further in excess of the advice. Recreational removals in 2015 were estimated at 737t, 228t in 2016, 223t in 2017 and 156t in 2018. To date, there has never been a Total Allowable Catch set for this stock. Because seabass can be bycaught in many fisheries, it could become a ‘choke species’ if vessel catch limits were introduced and seabass fell under the landings obligation. Monthly catch limits are instead in place for different gear types, but there is concern that the recent measures are not being universally adhered to.
Emergency measures in 2015 included stopping the offshore pelagic trawl fishery on spawning aggregations between January and April 2015, bag limits for recreational fishing, and increasing the Minimum Conservation Reference Size (MCRS) from 36cm to 42cm. This reduced not only pelagic trawl catches of sea bass, but also bycatch of sea bass in other fisheries. However, it also increased discards of below MCRS fish. Further measures have been introduced or developed since then. In 2019, the following management measures were in place:
For recreational fishing, 1 fish per fisherman per day can be retained from April-October in the North Sea (ICES 4b, 4c), west of Scotland (6a), and Celtic Seas (7a to 7k). This bag limit has been maintained from previous years, but the period during which fish can be retained has been extended. For the rest of the year they are limited to catch and release only.
Commercial fishermen are prohibited from catching, retaining, transhipping or landing bass caught in the South West Approaches (ICES 7b, 7c, 7j, 7k) or the Irish or Celtic Seas outside the 12 nautical mile limit of UK waters (in ICES 7g and 7a). In the North Sea (ICES 4b, 4c), English Channel (7d, 7e), Celtic and Irish Seas (7g and 7a inside the 12nm limit of the UK; 7f), and South West Approaches (7h), commercial fishing can take place at certain times of the year (January; April-December) with authorisation from the Marine Management Organisation. Fishing for bass in any of these areas is prohibited during February and March 2019 (spawning season). The number of vessels authorised to fish for seabass is limited to the number that caught seabass in 2015/2016.
Commercial shore fisheries, driftnets and pelagic trawling are prohibited. For other gears, the following limits apply: demersal trawl: up to 400kg/2 months and 1% of total daily catch; seine net: up to 210kg/month and 1% of catch; hooks & lines: 5.5 tonnes/year; fixed gillnets: 1.4 tonnes/year/vessel. These weight limits are an increase from the previous year.
It is estimated that with the above limits, the recreational sector’s share of 2019 catches will be 17%, while the commercial sector will catch 83% of the total. Bass that have been caught in contravention to these regulations (no authorisation, wrong gear, below minimum size etc.) must be discarded.
In Ireland, a moratorium on commercial fishing for bass has been in effect since 1990 and the species is restrictively managed for its valuable recreational sector and angling tourism industry. Recreational fisheries in Ireland are subject to bag limits of 2 fish in 24 hrs; a 40 cm minimum size limit; and a closed season from 15th May to 15th June annually.
The UK has 37 UK seabass nursery areas where certain types of fishing on seabass are prevented annually or seasonally. However, catching and discarding of seabass by trawlers fishing close to nursery areas means that juveniles are still being caught.
Discarding is estimated from a mix of sampling programmes and logbooks, and sampling is variable across fleets and years. Despite the increase in reported discards since 2016 for some countries, total discards are still considerably underestimated. Most discards are fish below the MCRS, and mostly from otter trawlers using 80-99 mm mesh in areas such as the inshore English Channel, where juvenile bass are most common.
Monitoring and enforcement includes the use of vessel monitoring systems (VMS) on board vessels over 12 m overall length; direct observations by patrol vessels and aerial patrols; inspections of vessels, gear and catches at sea and on shore, and verification of EU logbook data (for vessels over 10m) against sales documents. Small catches (up to 30kg) can be disposed of without documentation. Given the large number of small vessels landing small quantities of bass this is considered to add to the uncertainty in quantifying overall catches, although sampling by member states is required. Considerable uncertainties remain in the historical landings of sea bass by the under-10m fleets.
In the European Union (EU), EU fishing vessels can fish up to 12 nautical miles of any Member State coast, and closer by agreement. There is overarching fisheries legislation for all Member States, but implementation varies between fisheries, Member States and sea basins.
The EU Common Fisheries Policy (CFP) is the primary overarching policy. Its key environmental objectives are to restore and maintain harvested species at healthy levels (above BMSY), and apply the precautionary and ecosystem-based approaches to fisheries management. To achieve the MSY objective, the MSY exploitation rate is supposed to be achieved by 2020, but this seems unlikely to happen.
The CFP also introduced a Landing Obligation (LO) which bans the discarding at sea of species which are subject to catch limits. Some exemptions apply to species with high post-capture survival, and where avoiding unwanted catches is very difficult. These exemptions are outlined in regional discard plans. Despite quota ‘uplift’ being granted to fleets under the LO, available evidence suggests there has been widespread non-compliance with the policy, and illegal and unreported discarding is likely occurring.
Multi-Annual Plans (MAPs) are a tool for implementing the CFP regionally, with one in place or being developed for each sea basin. They specify fishing mortality targets and ranges for the main targeted species, as well as lower biomass reference points. If populations drop below these points it should trigger a management response. The MAPs also empower Member States to jointly apply measures such as closures, gear or capacity limits, and bycatch limits. There is concern however that the MAPs do not provide adequate safeguards to maintain all stocks at healthy levels.
The EU Technical Measures regulation addresses how, where and when fishing can take place in order to limit unwanted catches and ecosystem impacts. There are common measures that apply to all EU sea basins, and regional measures that vary between sea basins. Measures include Minimum Conservation Reference Sizes (MCRS, previously Minimum Landing Sizes, MLS), gear specifications, mesh sizes, closed areas, and bycatch limits.
The Control Regulation, which is being revised in 2019, addresses application of and compliance with the above, e.g. keeping catches within limits, recording and sharing data, and satellite tracking of vessels over 12 metres (VMS).
Criterion score: 0.5 info
An estimated 1,439 tonnes of seabass was caught in 2018, of which, 801t was commercial landings, 482t was discarded, and 156t was recreational catch. The commercial catches were by: Lines (52%), Bottom trawlers (14%), Fixed or drift nets (26%), Danish seine (3%), and Pelagic trawlers (1%). Catches are primarily by the UK, France, and the Netherlands.
Only a very small component of the otter trawl fisheries target sea bass and most of the sea bass catch by this gear is a bycatch in mixed demersal fisheries. Discarding of under-sized sea bass is relatively high in some areas, especially by otter trawlers using 80-99 mm mesh in areas such as inshore regions of the English Channel, where there are spawning grounds and juvenile bass are most common.
Demersal otter trawls use doors to hold nets open that penetrate the seabed, resulting in the abrasion of habitat features. The ground ropes, sweeps and bridles of the trawl can have similar abrasive impact. Most otter trawling occurs within the same historical areas, where yields are high and it is safe to trawl. Bycatches of non-target species can make up a high proportion of catch weight in demersal otter trawls. Otter trawls can take bycatches of protected, endangered and threatened species in certain circumstances. Bycatches of skates, rays and sharks (elasmobranchs) take place in most European otter trawl fisheries.
The main habitat protection measures are Marine Protected Areas, some of which are designated for benthic features. If those MPAs were found to be subjected to bottom trawling, MCS would consider it a default red rating unless there is evidence (e.g. environmental impact assessment) indicating the activity does not damage the integrity of the site.
Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.Basa, Tra, Catfish or Vietnamese River Cobbler
Bass, seabass (Farmed)
Bream, Gilthead (Farmed)
Cod, Atlantic Cod
Pollock, Alaska, Walleye
ReferencesEEA, 2018. European Anglers Alliance: Sea Bass Management Measures 2019 Agreed Today. Available at https://www.eaa-europe.org/news/13078/sea-bass-management-measures-2019-agreed-today.html [Accessed on 19.08.2019].
EU, 2019. Regulation (EU) 2019/472 of the European Parliament and of the Council of 19 March 2019 establishing a multiannual plan for stocks fished in the Western Waters and adjacent waters, and for fisheries exploiting those stocks. Available at https://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1554387217276&uri=CELEX:32019R0472 [Accessed on 12.07.2019].
ICES. 2019. Working Group for the Celtic Seas Ecoregion (WGCSE). ICES Scientific Reports. 1:29. 1078 pp. doi: 10.17895/ices.pub.4982. Available at http://www.ices.dk/sites/pub/Publication%20Reports/Expert%20Group%20Report/Fisheries%20Resources%20Steering%20Group/2019/WGCSE/01_WGCSE_2019.pdf [Accessed on 17.07.2019].
ICES. 2019. Sea bass (Dicentrarchus labrax) in Divisions 4.b-c, 7.a, and 7.d-h (central and southern North Sea, Irish Sea, English Channel, Bristol Channel, and Celtic Sea). In Report of the ICES Advisory Committee, 2019, bss.27.4bc7ad-h, https://doi.org/10.17895/ices.advice.4779. Available at http://ices.dk/sites/pub/Publication%20Reports/Advice/2019/2019/bss.27.4bc7ad-h.pdf [Accessed on 17.07.2019].
Seafish, 2019. RASS Profile: European sea bass in the English Channel, Irish, Celtic and southern North Seas, Demersal otter trawl. Available at https://www.seafish.org/risk-assessment-for-sourcing-seafood/profile/european-sea-bass-in-the-english-channel-irish-celtic-and-southern-north-seas-demersal-otter-trawl [Accessed on 17.07.2019]
MMO, 2019. Statutory guidance: Bass fishing guidance 2019. Published 14 February 2019. Available at https://www.gov.uk/government/publications/bass-industry-guidance-2019/bass-fishing-guidance-2019 [Accessed on 19.08.2019].
Nunny, L. 2011. The Price of Fish: A review of cetacean bycatch in fisheries in the north-east Atlantic
Ross and Isaac. 2004. The Net Effect. A WDCS Report for Greenpeace.
NSAC, 2017. Sea bass management in the North Sea. NSAC Advice ref 03-1617. Available at http://www.nsrac.org/wp-content/uploads/2016/12/3-1617-20161208-Sea-bass-Mgmt-in-the-N-Sea.pdf (Accessed July 2018).