More than 3,050 invertebrates species inhabit the Barents Sea benthos (Sirenko, 2001) and boreal-arctic species dominate in terms of biomass. Benthic areas with low abundance (less than 1,000 individuals/ m2) and biomass (less than 10-25 g/m2) are usually restricted to bottom depressions such as the western deep-water areas in the Bear Island Channel (Bjørnøyrenna) and Hopen Deep (Hopendypet) (Figure 4.3.11), deep-water areas between Franz Josef Land and shallow waters of the Novaya Zemlya Bank and deep-water areas in the Eastern Basin (Øst bassenget sør, Figure 4.3.11).
During the recent warming period (1998-2012), distinct trends were observed in abundance of fish species from different zoogeographic groups (Figure 4.3.54). The abundance of coldwater fish species (Arctic, mainly Arctic, and Arcto-boreal) decreased during the period between 2000 and 2010. However, a trend of slight increase has been observed since 2010 in the abundance of mainly arctic and Arcto-boreal groups.
Ecosystem surveys have shown exceptionally rapid growth of the snow crab – especially in the waters adjacent to the northern island of the Novaya Zemlya archipelago – and the expansion of its range in the north-east direction (Figure 4.3.30).
In recent decades, non-indigenous species which may be considered both “introduced” and “invasive” have appeared in the Barents Sea. Currently, 15 of them have been identified. These organisms entered the Barents Sea either in a natural manner — through the expansion of habitat due to global warming — or as a result of human activities, related to the intentional or accidental introduction of non-indigenous species.
Introduced species have been identified as major agents of global change and one of the main threats to marine systems because of their direct and indirect impacts on native ecosystems. Their effect on biodiversity, habitat structure, and economically important fisheries is a major source of concern (Dvoretsky and Dvoretsky 2010; Falk-Petersen et al. 2011).
Numbers of seabirds breeding in the Barents Sea Region have changed dramatically over the last 50 years. A recent assessment of population status and trends has been conducted, based on monitoring and census date for several species breeding in the western part of the Barents Sea (i.e., Norwegian mainland and Svalbard) (Fauchald et al., 2015). Resulting analyses indicate that breeding populations of subarctic pelagic auk species (common guillemot Uria aalge, razorbill
The environmental risks of oil and gas development in the region have been evaluated several times, and is a key environmental question facing the region. The focus of the debate is the risk of an accidental oil-spill during exploration or production. The consequences of such a spill depend on the activity, the location, time and potential exposure of environmental valuable species and areas. One of the environmental risks from future oil production can be associated with potential activities, which might influence near-shore areas, especially in ecologically valuable areas like the Lofoten-Islands and Pechora Sea. In addition, the Polar Oceanographic Front and the Ice Edge zone are particular sensitive areas.