Published: 25.08.2021 Updated: 06.09.2021
A total of three Norwegian and one Russian research vessel will set out to update and expand our knowledge of one of the world’s richest ecosystems.
The Barents Sea is a productive area, with more than 200 species of fish, thousands of benthic invertebrate species and diverse communities of plankton, seabirds and marine mammals inhabiting or visiting the area. The Barents Sea is a shelf sea and a transition zone between Atlantic and Arctic conditions. Inflowing Atlantic Water is relatively warm and gives boreal conditions in the western and southern areas, while Arctic Water is cold and gives sub-arctic and arctic conditions in the northern area.
During the last decades, the Barents Sea is changing rapidly from being cold in the 1980s to become warmer and record warm in 2016. Therefore, these annual cruises are invaluable to monitor the changes. The stocks of cod and haddock grew very large in 2009–2013. The capelin stock has been through tops and downs, while the polar cod stock is diminishing. Fish and benthic animals that prefer the warmer Atlantic waters are now found further north. Marine mammal species visiting the Barents Sea for summer feeding increase both in the number of species and individuals.
The data from the eco-cruise provide a basis for quota advice and recommendations for the overall management of the Barents Sea for both Norway and Russia as well as all other nations fishing on quotas in the area.
The Barents Sea has been monitored and investigated for more than a century. Norway and Russia have carried out more than 1850 occasional expeditions during this period. IMR and Scientists from IMR and a Russian sister institute in Murmansk (PINRO/VNIRO) meet annually since 1958 to discuss challenges and plan joint activities (cruises, conferences, meetings). The 0-group (young-of-the-year-fish) cruise started in 1965 and was the first joint cruise. Researchers wanted to find out why recruitment in fish stocks varies, in order to be able to predict how the stocks develop.
Since 2004, the 0-group cruise has been part of the eco cruise. This cruise has developed into the world's most comprehensive ecosystem cruise. These joint cruises have saved costs for the institutions and provide the opportunity to cover larger areas and several components of the ecosystem at the same time. Comparable data from these cruises and joint Norwegian-Russian stock assessments lead to robust stock advice and management.
The goal of the eco-cruise is to monitor the status and changes of the Barents Sea ecosystem to support scientific research and management advice. To understand changes in the cod stock, we also need to know about changes in environmental conditions (water, temperature, currents) and food supply for other organisms from larvae and jellyfish to fish, shellfish and other benthic organisms, as well as other predators (sea mammals and seabirds) who feed on the same food resources.
Observations of contamination tell us whether the fish that we desire for consumption is contaminated and how much. We also check for contamination that can cause damage directly to fish, marine mammals and seabirds. At three-year intervals, we check whether there is radioactive contamination in the sea, and how much debris is found in the water and on the seabed.
The cruise provides data on everything that is collected, from the bottom, the water column, the surface and the air. These data are collected at the same place at the same time every year. The data is widely used in ecological studies aimed at understanding contexts in an ecosystem, where everything and everyone is important and can influence each other.
RV “Johan Hjort” was the first to embark on this year’s eco-cruise. It will cover the most important capelin summer feeding areas, where there are also large numbers of predators preying on capelin – including cod, humpback whales, minke whales and many seabirds. These areas were recently assessed by researchers and proposed as a significantly valuable and vulnerable area (SVO).
RV “G.O. Sars” will start investigations in the western part of the Barents Sea. These areas are the gateway to the Barents Sea, where warm Atlantic plankton rich water masses rich flow in. Due to this inflow, the western and central Barents Sea do not freeze in winter. The Atlantic current mixes with the coastal current along the Norwegian coast and forms the “motorway” where fish eggs and larvae from the spawning fields are transported up to their nursery areas in the Barents Sea. Some of them grow up and return to the spawning grounds to continue the story.
RV “Helmer Hansen” will cover the far north of Norway’s territory, around and north of Svalbard. These areas were previously covered with ice from late autumn to summer but have now been completely or partially ice-free for several years. This leads to major changes for the Arctic community that are adapted to find food and shelter under the ice. When the cod stock and distribution area increased to the northern areas in 2010s, cod preyed also on limited Arctic resources. Climate change and the relocation of fish stocks are very important topics for the entire eco-cruise, where the areas around Svalbard are of great interest.
The Russian RV “Vilnjus” has started its journey in the eastern Barents Sea by measuring the temperature on the Kola section, one of the world’s longest temperature sections. The measurements give an indication of the temperature conditions in the entire sea, which in turn is of great importance for ecology and stock relocations. In addition, the Russians take similar ecosystem samples and data as the Norwegian cruise vessels. “Vilnjus” will end the cruise with a coordinated sampling with “J. Hjort” in capelin areas in the far north.
This research cruise is possibly the most advanced and complex ecosystem cruise in the world. Since 2004, this has led to better management of fishery resources and strengthened the knowledge base for the comprehensive, ecosystem-based management plan for the Barents Sea.
The knowledge is also used internationally by the IPCC, IPBES, Norwegian-Russian Environment and Fisheries Commissions, OSPAR and for national and international research projects. Scientific publications, university dissertations and master’s degrees based on this data base are regularly being presented.
Our annual eco-cruises show how important it is to invest time, human resources and good international contacts, if we are to be able to ensure sufficiently good data to understand what is happening and take the right measures at the right time. This is key to take care of the vital resources we find in the Barents Sea for eternity.