Anthropogenic litter were observed at every fourth (pelagic) and every second (bottom) station, and plastic dominated among all observations. Amounts of plastic and other litter are relatively low in comparison to other sea areas.
Due to poor coverage of the Russian Zone by BESS in 2018 it is impossible to compare distribution of litter and some parameters, for example average weight of litter in trawl, between 2019 and 2018. Plastic dominated among anthropogenic litter on the sea surface in 2019 (59% of observations, Fig. 3.9.8.1). The maximum surface observation of plastic litter was 0.331 m3, with an average of 0.014 m3. Wood was recorded in 39% of the observations. The maximum surface observation of wood was 2.8 m3, with the average of 0.4 m3. Metal, paper and rubber was observed singularly. Fishery related litter was recorded in 15.3% of plastic litter observations at the surface (Figure 3.9.8.2). Fishery related litter was represented by ropes and floats/buoys.
Figure 3.9.8.1 Type of observed anthropogenic litter (m3) at the surface in the BESS 2019 Taken from the 2019 BESS survey report (Prokhorova and Grøsvik 2020).
Figure 3.9.8.2 Litter observations of plastic at the surface indicated as fishery related and other litter in the BESS 2019 (crosses – occurrences of anthropogenic litter).Anthropogenic litter was observed in 25.8% of the pelagic trawl stations (Fig. 3.9.8.3). The number of litter recordings from both pelagic and bottom stations increased in the period since these recordings started (2010) to 2018. In 2010, 6.6% of pelagic trawls contained litter, 2.9 % in 2011 and 24.2 % in 2018 (ICES, 2019). Plastic dominated among all anthropogenic matter in pelagic trawls. Frequency of occurrence of plastic in pelagic trawls was approximately the same in all years. Thus, plastic was recorded in 96.5% of the stations with observed litter in 2019, in 94.7 % in the period of 2010-2013 and 95.6% in the period of 2014-2018 (ICES, 2019). The weight of plastic litter from pelagic trawls varied from 0.1 g to 23 kg with an average of 0.03 kg (except the single maximum catch of 23 kg). Other types of litter (wood, textile, paper and metal) were observed singularly. The maximum catch of litter by pelagic trawl was 10.5 kg per nm, with an average of 0.037 kg per nm. Litter was observed throughout the survey in the bottom trawl catches (43.8% of the bottom trawl stations) (Fig. 3.9.8.3). Plastic also dominated the litter content from the bottom trawls (82.3% of stations with observed litter in 2019 compared with 81 % of stations in the period of 2010-2013 and 88.7 % in the period of 2014-2018) (ICES. 2019). The weight of plastic litter in bottom trawls was from 0.1 g to 11.3 kg with an average of 0.04 g (except the single maximum catch of 11.3 kg). Wood was registered in bycatch in shallow waters in the south-eastern part of the Barents Sea, also in the northern part of the survey area (24.8 % of stations with observed litter). In 2019 more wood litter was observed than in previous periods (11.3% in 2010-2013 and 19% in 2014-2018) (ICES. 2019). Textile, paper, metal, rubber and glass were observed among the bottom trawl catches sporadically. The maximum catch of litter by bottom trawl was 21.0 kg per nm, with an average of 0.17 kg per nm. Litter from fishery was a significant part of plastic litter both in the pelagic and bottom trawls (63.4 % and 41.1 % respectively) (Figure 3.9.8.4).
Figure 3.9.8.3 Type of anthropogenic litter collected in the pelagic trawls (left) and bottom trawls (right). Size of circles indicate weight in the range of >0, >150g or > 1000 g for pelagic trawls or in the range of >0, >0.5 g or > 1000 g for bottom trawls. Crosses indicate trawl stations. Taken from the 2019 BESS survey report (Prokhorova and Grøsvik 2020).
Figure 3.9.8.4 Fishery plastic proportion among the plastic litter collected in the pelagic (to the left) and bottom trawls (to the right) in the BESS 2019 (crosses – trawl stations). 