Barents Sea Fisheries
- Sea surface temperatures are expected to increase in the next decades, with a concurrent decrease sea ice coverage. It is projected that the production potential of the Barents Sea will increase in future, but that beyond 2050 the projections suggest decreases in production potential.
- Due to a favourable climate and lower fishing pressure, the population sizes of cod and haddock are above the long-term average, though in recent years a decline in spawning stock biomass is observed
- The northward expansions of these two fish species have led to a community-wide shift in fish composition; boreal communities are now found further north and the local Arctic (cold-water affinity) community has been almost pushed out of the shelf area.
- The displacement of cod and haddock increases the connectivity in the Arctic ecosystem according to network analyses. This might have consequences for the resilience of the ecosystem.
- The snow crab population, an invasive newcomer in the Barents Sea, has spread westward and is now well established also in the Norwegian part of the Barents Sea. It is expected to have a potentially positive effect on demersal commercial species, including cod and haddock, which can feed on this resource.
Effects of climate change
Future predictions of stock development were not modelled in ClimeFish, but short term predictions done in collaboration with the Institute of Marine Research suggests that the population size of the North-East Arctic cod will decline up until 2024, whilst remaining above the long-term average, with the main predictors being the Atlantic Multidecadal Oscillation (AMO), temperature and salinity.
A westward expansion of the snow crab is likely to occur given current bottom temperature ranges, though the expansion will be limited by depth, whilst a 10C increase in temperature is likely to reduce the area of distribution.
The main threats of a continued warming of the BS include changes in trophic structures and the composition of benthic communities.
Risks and opportunities
A risk / opportunity analysis was not performed for the Barents Sea. It is likely though that some of the potential impacts and the associated risks produced in the analysis for ‘C5F West of Scotland’ will be similar for the Barents Sea. For example, a likely northward shift of species (including cod), driven by changes in temperature, will have a potentially major negative risk for the ecosystem. A change in species composition on the other hand may have both major opportunities and risk associated with it for the fishery.
A specific climate adaptation plan (CAP) was not developed for the Barents Sea. It is likely though that some of the CAP measures produced in the analysis for ‘C1F North-East Atlantic Pelagic Fisheries’ and the ‘C5F West of Scotland’ will be similar for the Barents Sea.
The fishing industry has to weigh off the cost / benefits involved with operating in distant fishing grounds and possible changes in species composition, while on a policy level allocation / sharing agreement may need to be revisited.
The vulnerability and risk assessments are being conducted in two ongoing national multidisciplinary projects. The projects are coordinated by the Marine Research Institute with WP leaders from UiT:
- “Barents Sea Ecosystem structure, functioning and vulnerability under climate change” (BSECO), focusing on ecological traits and fooweb structure and responses to external forcing and how, in turn, they can affect ecosystem dynamics
- “Assessing risks of cumulative impacts on the Barents Sea ecosystem and its services” (BARENTS-RISK), assessing cumulative impacts, including climate change, across sectors within one, unified framework including direct and indirect, foodweb mediated responses.