Herring are caught by static nets (gill or fixed net) in the coastal waters of the Central Baltic Sea.
Baltic herring is caught in coastal waters by trapnets and gillnets for human consumption. The trapnet and gillnet fisheries for herring are minor in comparison to the pelagic trawling fishery within the area. Incidental catch of non-target species (bycatch) is thought to be low, but, where incidental catch does occur species may include cod or sprat.
As the fisheries in this area also take sprat, species misreporting of herring has occurred in the past, and there are indications of sprat being misreported as herring. Recent legislation has forced catches to be sorted before landing, but the approach to this has been variable and might need further exploration. The bycatch level of other species such as juvenile cod is unknown. Currently, the eastern cod stock is concentrated in sub-divisions 25-26 and shows poor growth conditions, most likely due to the lack of food. This may be related to low abundance of herring in this area which is a prey species. Closures of the herring and sprat fisheries in areas where cod are more abundant could help mitigate this issue.
Gillnets and static nets in the Central Baltic sea have little impact upon the coastal seabed. However, static nets in the Baltic are known to impact harbour porpoise (Phocoena phocoena) populations (exceeding internationally adopted thresholds of acceptability in the Baltic Sea), grey seals and a variety of diving water-birds (including long-tailed ducks, scoters and divers amongst other species) especially in wintering areas. Diving water birds are especially vulnerable to being entangled in gillnets and other types of static nets.
The Baltic Proper harbour porpoise is listed as Critically Endangered (CR) by IUCN and HELCOM. All EU Member State assessments and the EU biogeographical assessment of the conservation status of the harbour porpoise in the Baltic Marine Region have been assessed as unfavourable-bad for the last three consecutive assessments under Article 17, reporting for the Habitats Directive (since 2001). ASCOBANS considers that the Baltic subpopulation of the harbour porpoise is of particular concern . HELCOM is deeply concerned about the population status of harbour porpoise in the Baltic Sea and convinced that the critical status of harbour porpoises in the Baltic Sea calls for immediate actions in order to safeguard their survival .
Following an EU request on emergency measures to prevent bycatch Baltic Proper harbour porpoise in the Northeast Atlantic, in May 2020, ICES concluded that the proposed measures by NGOs for the Baltic Proper harbour porpoise are appropriate to reduce the bycatch. However, several spatio-temporal and technical amendments are recommended. In the latest threat matrix developed by ICES WGMME (2019), threat levels for the Baltic Proper harbour porpoise were considered high for bycatch. Static gears (trammel nets, gillnets, and semi-driftnets) pose a considerably higher bycatch risk for porpoise than all other gear types. To immediately reduce bycatch of harbour porpoise, a set of five measures have been recommended by ICES, including the closure of important habitats, closures of areas during breeding season, and areas known to have high densities of animals, the mandatory use of pingers on static nets where animals are regularly present and during seasonal distribution. For marine mammals to attain a favourable or good conservation status, relevant EU legislation requires that bycatch of marine mammals should not exceed predetermined levels. For the Baltic Proper harbour porpoise management unit, to meet the management objective of achieving bycatches below PBR (<0.7 individuals per year), all fisheries of concern should be closed. Application of ICES advice and the proposed measures are yet to be displayed.
