Marine living resources of the Barents Sea – Ecosystem understanding and monitoring in a climate change perspective

Abstract

The Arctic is of special importance to the world, and it is changing rapidly. Uncovering the relationship between drivers of change and biological responses in the Barents Sea is therefore crucial for understanding the potential effects of climate change on the ecosystem in general and on commercially important species in particular. This thematic review provides an overview of the discussions related to long-and short-term variations in climate in the Barents Sea, what these physical changes really are, and how they may develop in the future. Furthermore, questions related to how these predicted climatedriven physical changes may alter ecosystems and the implications and future challenges that this represents for the management of resources in the area are raised. There is no doubt that to better understand the structure and function of an ecosystem, as well as to investigate the possible effects of climate changes, there is a need for thorough monitoring and data collection. The Barents Sea Ecosystem Survey (BESS) is used in several of the studies highlighted in this review. Therefore, we can provide a detailed description of the BESS and relate BESS research activities to other research initiatives in a thematic context.

High Latitude Epipelagic and Mesopelagic Scattering Layers—A Reference for Future Arctic Ecosystem Change

“…Although acoustics are regularly used to map the distribution of pelagic fish both in the Norwegian and Barents Seas (Toresen et al, 1998;Michalsen et al, 2013), there are only a restricted number of studies around the northern Atlantic where acoustic techniques have been applied in open ocean regions to examine large-scale acoustic backscattering structures (Melle et al, 1993;Kaartvedt et al, 1996Kaartvedt et al, , 1998Magnússon, 1996;Torgersen et al, 1997;Dale et al, 1999;Knutsen and Serigstad, 2001;Anderson et al, 2005;Pepin, 2013;Norheim et al, 2016;Siegelman-Charbit and Planque, 2016). Most studies have focused on the more accessible fjord populations of fish and plankton, addressing Frontiers in Marine Science | www.frontiersin.orgspecific issues related to predator prey interactions and diel vertical migration (Falk-Petersen et al, 2004;Kaartvedt et al, 2008;Berge et al, 2009Berge et al, , 2014Dypvik et al, 2012).…”

Evidence of Diel Vertical Migration of Mesopelagic Sound-Scattering Organisms in the Arctic

“…The DSL in the eastern part, which is closer to the shelf break, was dominated by larger fishes (including cod) as compared to further west (Knutsen et al, 2017, Table S1). Larger fishes also migrate on daily cycles, and e.g., cod migrations can span ranges up to 250 m (e.g., Godø and Michalsen, 2000;Michalsen et al, 2013). Thus, it is possible or even likely that the differences in diel migration across the northern Fram Strait section is linked to differences in species composition.…”

Patterns and drivers of megabenthic secondary production on the Barents Sea shelf

“…The first systematic large-scale study on Barents Sea megafauna results from the joint Nor wegian− Russian Ecosystem Survey (Michalsen et al 2013) and was published recently (Anisimova et al 2010. Jørgensen et al (2015) provided the first explicit, large-scale analysis of Barents Sea megafauna community composition and distribution patterns and identified a northern and a southern megafauna assemblage which can be divided further into 2 subregions each.…”

“…Benthic megafaunal abundance and biomass data were derived via the joint Norwegian−Russian Ecosystem Survey (Michalsen et al 2013). The dataset of 398 bottom trawl stations presented in this study was compiled by experts on 3 Norwegian and 1 Russian research vessel from August to October 2008 and August to October 2009.…”

“…However, the ongoing rapid retreat of sea ice raises questions concerning the current and future productivity of the area. The joint Norwegian−Russian Ecosystem Survey (Michalsen et al 2013) produced an extensive dataset on megabenthos that covers the entire Barents Sea. This dataset is unique in spatial coverage and resolution and thus allows us, for the first time, to model megabenthic secondary production for an entire Arctic shelf.…”