Herring or sild

Clupea harengus

Method of production — Caught at sea
Capture method — Pelagic trawl
Capture area — North East Atlantic (FAO 27)
Stock area — Celtic Sea (West of Scotland), Irish Sea (West of Ireland)
Stock detail — 6a, 7b, 7c
Picture of Herring or sild

Sustainability rating five info

Sustainability overview

Updated: July 2020.

Default red rating: ICES advices that there should be no fishing for herring in this area as the stock is depleted. Current fishing effort is for scientific sampling to try to improve understanding of the stocks in this area. There is no recovery plan in place, although one is being developed, and consequently no fishing should be occurring.

Fishing on this stock has low levels of bycatch and little to no habitat impacts. Scientific advice is to avoid negative impacts on the spawning habitat of herring, unless the effects of these anthropogenic activities have been assessed and shown not to be detrimental to the stock. There has been an increase in marine anthropogenic activity, especially in the area of marine renewables. The construction and development of wind farms, for example, results in disturbance to the seabed, as does aggregate extraction. Gravel is an essential habitat for spawning herring.

Owing to the stock being below Blim (the level at which the stock’s ability to reproduce may be impaired), with no precautionary recovery plan in place, and with catches continuing against the zero catch advice, this rating receives a Critical Fail.

Biology

Herring belongs to the same family of fish (clupeids) as sprat and pilchard. It can grow to greater than 40 cm, although size differs between races (distinct breeding stocks). Most herring landed are around 25 cm. Herring are sexually mature at between 3-9 years (depending on stock) and populations include both spring and autumn spawners. At least one population in UK waters spawns in any one month of the year. Herring have an important role in the marine ecosystem, as a transformer of plankton at the bottom of the food chain to higher trophic or feeding levels, e.g. for cod, seabirds and marine mammals. It is also considered to have a major impact on other fish stocks as prey and predator and is itself prey for seabirds and marine mammals in the North Sea and other areas. Herring spawning and nursery areas are sensitive to anthropogenic or human influences such as sand and gravel extraction.

Stock information

Criterion score: Critical Fail info

This is a data limited stock, and does not have reference points. Trends are used instead to determine the stocks state. The stock appears to be at critical levels and fishing pressure remains above sustainable limits, as catch continues against advice. The species has a medium resilience to fishing pressure.

The spawning-stock biomass (SSB) and Recruitment (R) have been declining since the millennia. In 2019, SSB was at the lowest recorded level in the time series (1957-2019), and considered to be below Blim (the level at which the stock’s ability to reproduce may be impaired). Fishing mortality (F) has reduced since 2016, with catches being limited by a scientific monitoring Total Allowable Catch (TAC). F has decreased from 0.68 to 0.31 between 2016 and 2019, in 2019 F was ~50% less than the previous year. The 2019-year class had the highest R (0.33) level since 2010.

ICES advises that when the precautionary approach is applied, there should be zero catch in 2021, as SSB is currently assessed to be close to the lowest level in the time-series and is likely to remain so in 2021, that is below possible reference points. Zero catch advice for this stock has been in place since 2016, when advice began, yet this advice has not been followed throughout with the assignment of a scientific fishery with a set annual TAC. This results in a default red rating.

The information presented here represents two stocks (herring in Division 6a north, and herring in divisions 6a south and 7b– c) assessed as one. This is because it is not possible to segregate them in commercial catches or surveys. However, combining the assessment issues a level of uncertainty.

Management

There is no precautionary management plan or recovery plan in place for this fishery. The stock is significantly decreasing and at critically low levels, with catches continuing against scientific advice.

ICES advises that when the precautionary approach is applied, there should be zero catch in 2021. However, a scientific fishery is in place and there is a set monitoring TAC. Assignment of a TAC when there is zero catch advice results in a default red-rating.

ICES recommends that a stock recovery plan for herring is developed, but no plan is currently in place despite the stocks critically low levels.

Two herring stocks in this area (herring in Division 6a North and herring in Divisions 6a South and 7b-c) are assessed as one, as it is not currently possible to segregate them in commercial catches or surveys. A rebuilding plan, which contains provisions for a monitoring TAC while the combined stocks remain below the Biomass limit (Blim), based on previous assessments, was evaluated by ICES in 2017. A key aim of the plan is to provide sampling opportunities for assessment and stock discrimination, whilst ensuring that the stock can be rebuilt. However, the plan was found not to be precautionary. A revised version of the rebuilding plan was submitted to ICES by the European Commission (EC) in 2018, but is yet to be evaluated. The continued uncertainty in the quality of the assessment and stock mixing need to be resolved in order to enable the evaluation of a rebuilding plan. The industry, in conjunction with the Pelagic Advisory Council, initiated a major genetic research programme in 2016 that aimed to obtain existing information on stock mixing in the fishing area. Preliminary analysis from the study represent two genetically-distinct populations. This project is now being developed further, with results which were due in 2020 yet to be released. There is a clear need to determine the relative stock sizes and to ensure that the smaller/weaker stock is adequately assessed and protected from over-exploitation.

In April 2016, ICES issued advice for a scientific monitoring fishery that could be obtained through a catch of 4,840 tonnes for herring in this area, at the request of the EC. The EC established a monitoring TAC of 5,800 tonnes in 2016 (which also included Divisions 5b and 6b) which was maintained up until 2019. In 2020, the monitoring TAC decreased to 4,840 tonnes in line with advice. The annual monitoring TAC was exceeded in 2016 (by 20%) and 2017 (by 10%) but catches have been lower than the TAC since. In 2018 and 2018 catches were 4% and 41% under the agreed TAC. However, as no rebuilding plan is established, there should be no fishing.

Discards are considered negligible.

Scientific advice is to avoid negative impacts on the spawning habitat of herring, unless the effects of these activities have been assessed and shown not to be detrimental to the stock. There has been an increase in marine anthropogenic activity, especially in the area of marine renewables. The construction and development of wind farms, for example, results in disturbance to the seabed, as does aggregate extraction. Gravel is an essential habitat for spawning herring.

Beyond the monitoring TAC, harvesting of herring is controlled through an EU Minimum Landing Size (MLS) of 20cm which is above herring size at maturity of around 17cm. The Republic of Ireland’s fisheries for the 6a South and 7.b-c stock are managed by local committees. These committees each have a set of local management objectives.


The UK is due to leave the EU on 31st December 2020, and new UK Fisheries legislation is being developed during 2020. MCS will update ratings with new management information when new legislation comes into force.

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).

Capture Information

Herring are caught by pelagic trawls off the coast of the West of Scotland and West of Ireland, in the Celtic Sea and Irish Sea.

The major part of the herring fishery in the area is carried out by vessels from Ireland and the UK; vessels from the Netherlands, Germany and the Faroes participate in the fishery to a lesser extent. The fishing season runs from late autumn into the spring; 1st October to the end of March the following year. This seasonal herring fishery, is exploited in the open sea by pelagic trawls (single, pair, and freezer-trawlers), with 100% of catch taken by pelagic trawl in 2018 and 2019. Ring netters have been known to participate, but catch is negligible. Herring fisheries are well targeted and tend to be clean with little bycatch of other fish.

The pelagic fisheries on herring are deemed to be some of the cleanest fisheries in terms of bycatch, disturbance of the seabed and discarding. The pelagic spring spawning herring fishery in the West of Scotland and West of Ireland, has little impact upon the seabed, although seabed contact can sometimes occur. Incidental catch of non-target species (bycatch) is negligible. Where incidental catch does occur species may include sprat, horse mackerel or mackerel. Pelagic trawls can be associated with bycatch of marine mammals. Nonetheless, Scottish observer programs, which have been running since 1999, have never recorded any catch of cetaceans within this fishery. Occasional catches of seals have been recorded but it is unclear when this last occurred and what species have been effected. Therefore, interactions with Protected, Endangered or Threatened Species is considered to be low.

A potential impact of the herring fishery is the removal of fish that could provide other ecosystem services. Herring are an important forage fish, and important planktivores, and are an integral part of the ecosystem. The ecosystem needs a biomass of herring to graze the plankton and act as prey for other organisms. Ecosystem models of the West of Scotland show herring to be an important mid-tropic level species along with sprat, sandeel, and horse mackerel. They also predate on fish eggs, such as cod, and recent work suggests a link between herring biomass and North Sea cod. If herring biomass is very low other species, such as sandeel, may replace its role or the system may shift in a more dramatic way. There is, however, no recent research on the multispecies interactions in the food web in which herring interact and it is difficult to predict the impact of increasing or reducing the herring biomass on the ecosystem functions as a whole.

Research suggests that herring recruitment is better in cooler temperatures, so any increase in sea surface temperature could have negative impacts on the stock.

References

Binohlan, C. and Nicolas, B. (Editors) (2020). Atlantic herring (Clupea harengus). Available at https://www.fishbase.se/summary/Clupea-harengus.html [Accessed 06.07.2020]

EC (1983). COUNCIL REGULATION (EEC) No 2931/83 of 4 October 1983 amending Regulation (EEC) No 171 /83 laying down certain technical measures for the conservation of fishery resources. Available at https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:31983R2931&from=EL [Accessed 18.06.2020]

ICES (2019). Stock Annex: Herring (Clupea harengus) in divisions 6.a and 7.b–c (West of Scotland, West of Ireland). Available at https://www.ices.dk/sites/pub/Publication%20Reports/Stock%20Annexes/2019/her.27.6a7bc_SA.pdf [Accessed 06.07.2020]

ICES (2020). Herring Assessment Working Group for the Area South of 62degrees N (HAWG). ICES Scientific Reports, 2:60. 1054 pp. Available at http://www.ices.dk/sites/pub/Publication%20Reports/Expert%20Group%20Report/Fisheries%20Resources%20Steering%20Group/2020/HAWG/01%20HAWG%20Report%202020.pdf [Accessed 06.07.2020]

ICES (2020). Herring (Clupea harengus) in divisions 6.a and 7.b–c (West of Scotland, West of Ireland). In Report of the ICES Advisory Committee, 2020. ICES Advice 2020, her.27.6a7bc. https://doi.org/10.17895/ices.advice.5944. Available at http://ices.dk/sites/pub/Publication%20Reports/Advice/2020/2020/her.27.6a7bc.pdf [Accessed 06.07.2020]