Human activities and its effects in the Barents Sea
Northern shrimp (Pandalus borealis)
Norwegian and Russian vessels harvest northern shrimp over the stock’s entire area of distribution in the Barents Sea. Vessels from other nations are restricted to trawling shrimp only in the Svalbard zone and the Loophole — a piece of international waters surrounded by the EEZs of Norway and Russia. No overall TAC has been set for northern shrimp, and the fishery is regulated through effort control, licensing, and a partial TAC in the Russian zone only. The regulated minimum mesh size is 35mm. Bycatch is constrained by mandatory sorting grids, and by
Minke whale (Balaenoptera acutorostrata)
Management of the minke whale is based on the Revised Management Procedure (RMP) developed by the Scientific Committee of the International Whaling Commission. Inputs to this procedure are catch statistics and absolute abundance estimates. The present quotas are based on abundance estimates from survey data collected in 1989, 1995, 1996–2001, 2002–2007 and 2008–2013. The most recent estimates (2008–2013) are 89 600 animals in the Northeastern stock, and 11 000 animals for the Jan Mayen area, which is exploited by Norwegian whalers.
Fishing activity in the Barents Sea is tracked by the Vessel Monitoring System (VMS). Figures 188.8.131.52-184.108.40.206 show fishing activity in 2017 based on Russian and Norwegian data. VMS data offer valuable information about temporal and spatial changes in fishing activity. The most widespread gear used in the Barents Sea is bottom trawl; but long lines, gillnets, Danish seines, and handlines are also used in demersal fisheries. Pelagic fisheries use purse seines and pelagic trawls. The shrimp fishery used special bottom trawls.
The level of discarding in fisheries is not estimated, and discards are not accounted for in stock assessments. Both undersized fish and by-catch of other species can lead to discarding; fish of legal size but low market value are also subject to discarding to fill the quota with larger and more valuable species (known as high-grading).
Discarding is known to be a (varying) problem, e.g., in haddock fisheries where discards are highly related to the abundance of haddock close to, but below, the minimum legal catch size. Dingsør (2001) estimated discards in the commercial trawl fishery for Northeast Arctic cod during 1946-1998, and the effects on the assessment. Sokolov (2004) estimated cod discard in the
Mesozooplankton play a key role in the Barents Sea ecosystem by transferring energy from primary producers to animals higher in the food web. Geographic distribution patterns of total mesozooplankton biomass show similarities over time, although some inter-annual variability is apparent. Challenges in covering the same area each year are inherent in such large-scale monitoring programs, and inter-annual variation in ice-cover is one of several reasons for this. This implies that estimates of average zooplankton biomasses for different years might not be directly comparable.
Benthos is an essential component of the marine ecosystems. It can be stable in time, characterizing the local situation, and is useful to explain ecosystem dynamics in retrospect. It is also dynamic and shows pulses of new species distribution, such as the snow crab and the king crab, and changes in migrating benthic species (predatory and scavenger species such as sea stars, amphipods and snails with or without sea anemones). The changes in community structure and composition reflect natural and anthropogenic factors. There are more than 3000 species
Zero group fish are important consumers on plankton and are prey of other predators, and, therefore, are important for transfer of energy between trophic levels in the ecosystem. Estimated total biomass of 0-group fish species (cod, haddock, herring, capelin, polar cod, and redfish) was 1.92 million tonnes during August-September 2017; slightly above the long term mean of 1.76 million tonnes (Fig 3.5.1). Biomass was dominated by cod and haddock, and mostly distributed in central and northern-central parts of the Barents Sea.
Most Barents Sea fish species are demersal (Dolgov et al., 2011); this fish community consists of about 70-90 regularly occurring species which have been classified into zoogeographical groups. About 25% are Arctic or mainly Arctic species. The commercial species are all boreal or mainly boreal (Andriashev and Chernova, 1995), except for Greenland halibut (Reinhardtius hippoglossoides) that is classified as either Arcto-boreal (Mecklenburg et al., 2013) or mainly Arctic (Andriashev and Chernova, 1995).
Phytoplankton development in the Barents Sea is typical for a high latitude region with pronounced maximum biomass and productivity during spring. During winter and early spring (January-March), both phytoplankton biomass and productivity are relatively low. Spring bloom is initiated during mid-April to mid-May and may vary strongly from year to year. Bloom duration is typically about 3-4 weeks and is followed by a reduction in phytoplankton biomass mainly due to nutrient exhaustion and grazing by zooplankton. Later in the fall when the increasing winds start to mix the upper layer and bring nutrients to the surface, a short autumn bloom can be observed. However, the timing of phytoplankton development can vary
There were no special researchers on marine mammals on board of Norwegian vessels during ecosystem survey. However, the Norwegian observers of seabirds on boards «Eros», «Johan Hjort», and «Helmer Hansen», as far as possible in parallel also did observations of marine mammals.
8 species of marine mammals were observed during the observation period in the research area, reaching a total of 899 individuals.
Mercury is the single most toxic element for seabirds. Mercury, along with Cadmium and lead, is one of the heavy metals that are of environmental concern as it can be toxic at levels only moderately elevated above natural ambient levels.
The surface sediments, i.e. the predominant sediment type of the upper ~ 50 cm of the seabed, form the uppermost part of a sediment sequence covering the rocks of the Barents Sea. This sediment sequence varying in thickness from a few to several hundred meters and was mainly deposited during the Quaternary (the last 2.6 million years), a time period where glaciations took place repeatedly.
The map service shows the grain size of seabed surface sediments of the Barents Sea. The map has been compiled in cooperation between the Geological Survey of Norway, Trondheim (Aivo Lepland), and OAO "SEVMORGEO", St. Petersburg (Aleksandr Rybalko), in the frame of the Norwegian-Russian Environmental Commission Workplan 2013-2014, OECEAN 5. Existing maps produced by various organizations served as a basis for the compilation.
This biotope map, covering the entire Barents Sea, has been compiled in collaboration between the Geological Survey of Norway, the Norwegian Institute of Marine Research (IMR) and the Russian Polar Research Institute of Marine Fisheries and Oceanography (PINRO) in the frame of the Norwegian-Russian Environmental Commission Workplan for 2011-2013 and 2013-2015.
The protected areas in Northwest Russia are divided into different categories of protection and management. In strict nature reserves (zapovednik) no economic activities are permitted. National parks are designated to nature conservation, research, educational and cultural purposes as well as controlled recreational activities. In national parks there are restrictions to the management of natural resources. Nature parks (prirodnyi park) are the equivalent of the Norwegian
Scientists, managers and commercial fishermen from Northern Norway, Finland and north-west Russia, White Sea area combined their efforts in the Kolarctic salmon project (2011-2013), with the aim of providing a better knowledge-base for the countries salmon management. Within this joint and unique effort bio-specimen were sampled along the North-Norwegian coast and in Russian Barents and White Seas generating the most comprehensive ecological and genetic datasets for Atlantic salmon (Salmo salar).