Species removal by fishing and hunting

Fishing and hunting are traditional sources of livelihood in all Baltic Sea countries. Hunting has a minor role today, but fishing is still an important source of food and income. Stock assessments show that three out of nine internationally assessed fish stocks achieve good status with respect to both biomass and fishing mortality rates. Recreational fishing may contribute considerably to the total mortality, especially in coastal areas, but estimates of its magnitude are uncertain. A current challenge to be met by the fishing sector is to ensure resource utilisation in line with the ecosystem-based approach.

Commercially exploited fish

The Baltic Sea fisheries target both marine and freshwater species, but the most important species for the commercial fisheries are marine (Box 4.6.1). Cod, herring and sprat represent about 95 % of the total catch in biomass terms. The fish is used for human consumption, but industrial use represents a large share, as oil, fish meal or animal fodder, depending on the market conditions. Other important commercial species are plaice, flounder, dab, brill, turbot, along with the migratory species salmon, and sea trout. Common commercial species with freshwater origin include pike, perch, pikeperch, vendace, and whitefish.

The Baltic Sea fisheries also catch eel, classified as a widely distributed species with a population that extends over several marine regions but which has declined dramatically (see also Box 5.3.1 in Chapter 5.3 Fish). Recreational fishing mainly targets the same stocks as commercial fisheries. Incidental by-catches of birds and mammals in connection to the fisheries are evaluated in Chapter 5.4 Marine mammals and Chapter 5.5 Waterbirds.

The overall objective of the Baltic Sea fisheries is to ensure economically, environmentally and socially sustainable use of fisheries resources in alignment with the ecosystem-based approach. Long term management plans for the internationally managed fish stocks aim to ensure that these are capable of producing a maximum sustainable yield (MSY), as mainly being regulated by the exploitation rate (EC 2016).  The status evaluation presented here was based on fisheries management advice provided by the International Council for the Exploration of the Sea (ICES 2017b-f). Two aspects: fishing mortality and spawning stock biomass, were evaluated separately for each stock. Status was evaluated against the condition that the average assessment ratio during 2011-2016 should achieve the reference values for both fishing mortality and spawning stock biomass (See also Box 4.6.2).

Assessment result

One demersal stock (plaice; Pleuronectes platessa) and two herring stocks (Clupea harengus) achieve good status with respect to both fishing mortality and spawning stock biomass during 2011-2016 (Figure 4.6.1). Three demersal and three pelagic stocks fail the reference value for at least one of these indicators; both two cod stocks (Gadus morhua), sole (Solea solea), two of the herring stocks, and sprat (Sprattus sprattus; Figure 4.6.2). The combined status was not possible to evaluate for eight demersal stocks (representing flatfishes).

At the level of each indicator, fishing mortality is assessed as too high for two demersal stocks and three pelagic stocks assessed for this indicator, whereas eight of the assessed stocks are fished at a level consistent with maximum sustainable yield. Spawning stock biomass is below the biomass reference point, indicating not good status, for two out of four assessed demersal stocks, and for one of the pelagic stocks.

Among the migratory species, slightly less than half of the salmon stocks (Salmo salar) are assessed to meet the criteria for maximum sustainable yield for 2016, or 14 out of 32 river stocks, also including consideration of recreational catches (ICES 2017d-e). With a few exceptions, the rivers in the northern Baltic Sea area present a better status for salmon than the southern ones. A reduced fishing of sea trout (Salmo trutta) was advised for the Gulf of Bothnia, the eastern part of subdivision 26 and the southern parts of subdivisions 22 and 24, to protect weak wild populations in these areas (ICES 2017f).

The status of the widely distributed European eel (Anguilla anguilla) is critical, based on stock size and many sources of mortality in addition to fishing (ICES 2017g, Box 5.3.1 in Chapter 5.3 Fish).

Figure 4.6.1. Number of internationally managed fish stocks in good and not good status, with respect to fishing mortality (left), spawning stock biomass (middle), and regarding both of these aspects together (right). The colours denote if the average indicator value during 2011–2016 achieves (green) or fails (red) the 2016 reference point. The number of fish stocks not included in the applied analytical assessment framework is indicated in white. Source: ICES (2017a-b).

The level of fishing mortality has been similar over the past ten years for most pelagic stocks, but has been increasing for herring in the Gulf of Bothnia[1] (Figure 4.6.3). The fishing mortality of sprat was too high in five of the assessed years, but achieved the reference value in 2016. With respect to demersal species, the fishing mortality of sole and plaice in the Western Baltic has decreased during the past ten years, to currently achieving their F_MSY reference values. The fishing mortality of Western Baltic cod has been very high above the reference value during all of the same time period (Figure 4.6.3). For Eastern Baltic cod, the relative fishing mortality has, with a few exceptions, been too high over the past decades (No graph; ICES 2017c).

Figure 4.6.3. Temporal development of fishing mortality relative to the reference point for demersal and pelagic Baltic Sea fish stocks assessed by the Maximum Sustainable Yield approach. Upper row, left: The demersal stocks sole (Solea solea), Western Baltic cod (Gadus morhua), and plaice (Pleuronectes platessa). Upper row, right: sprat (Sprattus sprattus). Lower row: herring (Clupea harengus). The green line shows the threshold value against which the average fishing mortality over 2011-2016 is evaluated. Source: ICES.

With respect to size structure, a decrease in the biomass of larger fish is noted for Eastern Baltic cod over the past ten years, in particular for fish larger than 40 cm. The relative harvest rate for larger cod is assessed as higher than the average of the stock (ICES 2017c, see also Figure 5.3.6 in Chapter 5.3 Fish).

Impacts and recovery

Impacts of overfishing include depleted fish stocks and reduced biomass. Since fisheries are typically focused on specific species and larger fish, they may also cause structural changes to populations and the food web. Such changes in overall species composition, and a decreased size and age structure of populations, have been seen both in the Baltic and adjacent areas (Cardinale et al. 2009, Eero et al. 2008; Svedäng and Hornborg 2014, see also Chapter 5.6 for food web aspects). Overfishing, and the associated changes at population and ecosystem level, affect long term fishing opportunities and food provision, since the changes in population or food web structure make the depleted stocks less productive and more vulnerable to environmental pressures (Berkeley et al. 2004, Stige et al. 2017).

Fisheries activities in eight Baltic Sea countries are regulated by the EU Common Fisheries Policy (CFP). In 2009, the European community and the Government of the Russian Federation agreed to cooperate over fisheries and conservation of living marine resources in the Baltic Sea. The current revision of the common fisheries policy was adopted in 2013 and aims to promote environmentally, economically and socially sustainable fishing, including measures to end overfishing and eliminate fish discards, for example. Currently, multi-annual plans are in place for the main part of the internationally managed fish stocks, and adjustments to fishing gear are undertaken to mitigate negative impacts on the ecosystem and fish stocks (EC 2016).

In addition to the targeted species and size classes, unselective fishing causes mortality of smaller sized fish and non-target fish species (as well as incidental by-catches of birds and mammals; see Boxes 5.4.1 and 5.5.1). The unwanted catch of fish has been mostly discarded in the past, and has been monitored and included in stock assessments for cod and some flatfishes. Since 2015, there has been a discard ban in place for cod, sprat, herring and salmon, and since 2017 for plaice. In coming years, the effect of these measures are to be evaluated.

Hunting of seals

Seals have been hunted historically for skin, fur, meat and fat, and they were an important source of income for people, particularly in the Northern Baltic Sea. Seals were also considered a nuisance due to their competition with fisheries, and hunting was encouraged. During the 1900s, bounties were even paid for hunting seals. A combination of hunting and environmental factors led to a dramatic decline in seal populations.

In the 1970s and 1980s, seals were protected by all countries in the Baltic Sea region. The number of seals has increased, and today conflicts with human fishing activities have re-emerged in an increasing number of areas. As a result, controlled hunting is allowed for grey seals in Denmark, Estonia, Finland and Sweden, ringed seals in Finland and Sweden, and harbour seals in Denmark and Sweden. The highest permissible annual quota among these countries is around 2,000 grey seals, 230 ringed seals and 235 harbour seals combining information from all countries. The reported hunting is often below the quotas (Table 4.6.1), however the scale of illegal hunting is not known.

Incidental by-catch of seals in fishing gear is an additional source of human induced mortality for seals that is not included here (Box 5.4.1 in Chapter 5.4 Marine mammals).

According to Baltic Sea regional recommendations there should be no hunting of seal populations if they are below a safe biological level, defined by a so called limit reference level (see also Chapter 5.4 Marine mammals). Also, hunting of populations above this level is only allowed if their growth rate is positive. These principles are followed in the Baltic Sea region at this time[2].

Hunting of waterbirds

The legislation for bird hunting is highly variable among countries. Waterbirds are hunted in some countries, although the timing is regulated, with hunting prohibited during the spring migration and breeding season (EC 2009). For example, in Denmark there is no hunting of waterbirds allowed between 1 February and 31 August. Southern Baltic Sea countries have a more extensive protection of bird species. For example all sea ducks in Poland are protected, and bird hunting is not permitted within a 3,000 metre strip between the coast and the sea or for 5,000 metres onto land (Polish hunting law 2018). In effect, ducks can be hunted on inland waters but are protected at the coast, for example mallard (Anas platyrhynchos), Eurasian teal (Anas crecca), common pochard (Aythya ferina) and tufted duck (Aythya fuligula). A similar legislation is in place in many other countries. Hunting in spring is permitted on the Åland islands.

Where hunting is permitted, common game species include common eider (Somateria mollissima), Eurasian teal, mallard, and Eurasian wigeon (Anas penelope). Long-tailed duck (Clangula hyemalis) is partially hunted (Table 4.6.2). The velvet scoter (Melanitta fusca) is hunted in Denmark (Asferg 2016) and protected in Sweden. Species hunted only in some countries include goosander (Mergus merganser), tufted duck and red-breasted merganser (Mergus serrator), as well as garganey (Anas querquedula), pintail (Anas acuta), shoveler (Anas clypeata) and gadwall (Anas strepera). In addition, waterbird populations are hunted elsewhere along their flyways. In Denmark, hunting of female common eider is no longer permitted in any season since the 2014/2015 season, and hunting of female long-tailed duck and velvet scooter is expected to be similarly prohibited from the 2018/2019 season, in accordance with the AEWA International Single Species Action Plan.

The great cormorant (Phalacrocorax carbo) is culled after derogation in some countries to mitigate damages to fish stocks and fisheries (HaBiDes 2017). Approximately 3,200 cormorants per year are shot in Denmark, 500 in Estonia, 700 in Finland (Åland), 1,700 in Germany[3], and 2,100[4] in Sweden. As part of such predator control programs, some countries also spray eggs with a substance to prevent them from hatching.

Birds are also decimated by other human induced pressures, such as oil spills and incidental by-catch, with unknown total level (see Box 5.5.1 in Chapter 5.5 Waterbirds).

Most of the hunted waterbird species listed in Table 4.6.2 are included in the HELCOM core indicators on waterbirds (Chapter 5.5 Waterbirds). The long-tailed duck and common scoter are not included due to the current assessment methodology. The numbers of velvet scoter and long-tailed duck have decreased markedly over time, and the long tailed duck is categorised as endangered in the HELCOM Red List (HELCOM 2013b). Similarly, the common eider and velvet scoter, amongst other waterbird species, are also on the HELCOM Red List.