The 2020 ecosystem survey collected 95 species from 29 families. It is 4 species and 1 family more than in 2019. Distribution of the groups have not changed since the previous year, but the larger geographical coverage of the survey allowed to uncover a large part of the Arctic and mainly Arctic species habitat (Fig. 3.8.1).
Zoogeographical groups of non-commercial species
By E. Johannesen (IMR), T. Prokhorova (PINRO) and B. Husson (IMR)
As usual boreal and mainly boreal species occurred mainly in the southern and southwestern part of the Barents Sea, while arctic and mainly arctic species in the northern and north-eastern part. Arctic-boreal species were found in the central and northern part of the area.
There is no trend in spatial distribution changes of species of each zoogeographical group in recent years (Fig. 3.8.2).
The last two years the median catches for Arctic species have increased, and it is the highest values since 2013 (Fig. 3.8.3). It should be noted however, that variation in survey coverage might influence the results (for more detail see section 2.6. Progress report on ToR (f) in this report).
A biogeographic score was assigned for all species according to their zoogeographic affiliation (Andriashev and Chernova, 1995). This index was averaged per trawl, weighed by the relative abundance of each species in the trawl. Maps of the “arcticness” of the catches is plotted in Fig. 3.8.4, This shows a decrease in proportion of arctic species in trawls until 2008/2010, then a stabilisation of the situation. However, the survey coverage has been very variable, and the index should be refined to take variable sampling coverage into account (see Fig. 3.8.4).