Herring or sild

Clupea harengus

Method of production — Caught at sea
Capture method — Pelagic trawl
Capture area — North East Atlantic (FAO 27)
Stock area — Western Baltic
Stock detail — 20-24 and IIIa (Spring spawners)
Picture of Herring or sild

Sustainability rating three info

Sustainability overview

Spawning stock biomass for this stock is too low (below the MSY trigger level of 110,000 t). Fishing pressure is too high (above F MSY level).

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

Stock Area

Western Baltic

Stock information

The most important pelagic fish in the Baltic Sea fisheries are herring and sprat. Their distribution varies with season, food availability, hydrography etc. Herring occur throughout the Baltic Sea, including the Gulf of Bothnia, Gulf of Finland and Gulf of Riga. Sprat are confined to areas south of the Aaland Islands and are mainly found in the open sea areas. Herring populations include both spring and autumn spawners. Previously autumn spawning herring dominated the herring populations, but there was a change in the 1960s, and since then spring spawning components have dominated the populations.
Herring populations form a continuous chain extending from the North Sea to the northernmost parts of the Baltic Sea. In the western Baltic (Sub-divisions 22-24) the spring spawning stock of herring dominate. These herring spawn in the western Baltic Sea, but migrate to feeding areas in the Kattegat, Skagerrak and the eastern part of the North Sea, where they mix with the North Sea herring. Both spring and autumn herring can be further divided into two population types - the sea and the coastal or Gulf herring. Within each population there are numerous sub-groups. Herring in the western Baltic (Sub-division 22-24) are assessed as one stock. Herring in the eastern Baltic are assessed as four stocks, i.e. herring in Sub-divisions 25-29 and 32, herring in the Gulf of Riga, herring in Sub-division 30 and herring in Sub-division 31. The herring in the central part of the Baltic Sea (Sub-divisions 25-29+32) is much the largest stock. The separation of stocks is a compromise between the large number of stocks/populations identified on a biological basis, and the ability to allocate catches to stocks. Also, management of the herring stocks is not possible on population by population basis.

The spawning-stock biomass (SSB) in this area reached its lowest point in the time-series in 2011 and has been between Blim and Bpa in the years after. Fishing mortality (F) was at a historical low, below FMSY, in 2014. F increased in 2015 and 2016, and is now above FMSY. The stock remains in a low production period, and recruitment was at record low in 2015 and 2016. ICES advises that when the MSY approach is applied, catches in 2018 should be no more than 34 618 tonnes. This advice applies to the catch of western Baltic spring spawners (WBSS) in subdivisions 20-24 and the eastern part of Subarea 4.

Management

An EU Baltic Sea Multiannual Plan was established in 2016 and applies to herring in subdivisions 22-24, which is part of the distribution area of the Western Baltic Spring Spawning (WBSS) stock. This plan is not adopted by Norway with whom the stock is shared. There is an agreed TAC-setting procedure between the EU and Norway for herring in Division 3.a.

Capture Information

In the Baltic, herring is mainly exploited in the open sea by pelagic trawls (single and pair trawls), and in coastal waters during spawning time, by trapnets, pound-nets and gillnets. Static nets in the Baltic are known to impact the harbour porpoise population, grey seals and a variety of diving waterbirds, and pelagic trawls can be associated with cetacean bycatch. National regulations introduced in 2009 in Division 111a has limited misreporting substantially. The minimum landing size for herring in EU waters is 20cm (18cm in Skagerrak/Kattegat), maturity is at around 17cm.

References

ICES Advice 2017 http://ices.dk/sites/pub/Publication%20Reports/Advice/2017/2017/her.27.20-24.pdf
http://www.fishbase.org/Summary/SpeciesSummary.php?ID=24&AT=herring