Due to climatic changes, ocean currents shift and thereby create new upwelling areas in the Arctic Ocean. Expert Dr. Katya Uryupova from The Arctic Institute explains the situation and the consequences.
There are well known areas of coastal upwelling activities on Earth, which occur mostly near the Equator and in the Southern Hemisphere. Created by winds and the rotation of our planet, deep and cold waters are brought to the surface of the ocean, a process called upwelling. Rich in oxygen and nutrients, these waters appear as an environment supporting biological production – the growth of phyto- and zooplankton, which becomes a food source for fish, birds, and marine mammals. Due to these characteristics, upwelling zones are considered as areas of intense commercial fisheries. Caused by climate change, hydrological characteristics of the northern waters, and upwelling zones, may alter dramatically, and this may result in extension of the fisheries zones in the Arctic Ocean and the adjacent seas, as well as in changing the established commercial and traditional fishing activities in the frigid waters in the future.
Changing hydrology of the Arctic Ocean and adjacent seas
Climate change is currently transforming the Arctic region. Among significant recognized alterations caused by this complex process in the Arctic Ocean and the adjacent seas are: retreating sea ice, deviations in precipitation, hydrology, temperature, and productivity characteristics of the marine environment.
In fact, recent scientific data show that with retreating sea ice, the northern waters are becoming areas with increased upwelling effects at the Arctic continental shelf. For instance, in transition zones between the Arctic and Sub-Arctic regions, i.e. the Atlantic and the Pacific gateways, where sea ice coverage has retreated dramatically over past decades, the intensification of the hydrological cycle may impact the precipitation characteristics of the area and the river runoff. In addition, scientists believe that current changes may cause the weakened stratification with increased vertical mixing in the Arctic Ocean waters, like those brought by Atlantic inflows in the Eurasian part of the Basin.
The cyclones are fundamental to Arctic climate forcing significant change in hydrology of the area, as they become long-lived and numerous there. Increasing impact of cyclones entering the region from the North Atlantic may create certain zones with the intensified upwelling effect, especially in the areas with steep underwater slopes. Scientists say that cyclones bring strong winds which drive changes in sea ice coverage and create waves resulting in massive atmosphere-to-surface turbulent ocean processes.
In 2022, the strongest Arctic cyclone ever recorded was observed in East Greenland and then tracked on the way to the Barents and the Kara Seas. The cyclone caused a massive weekly loss of regional sea ice area and surface wind speeds, and generated ocean waves more than 8 m high that impinged on sea ice in the Barents Sea. The Svalbard area may become one of those zones where the Atlantic water may cause upward motion of deep waters along the slope. With retreating sea ice, the slope regions are expected to be more exposed to cyclones and stronger winds, creating a nutrient fueling and becoming even more attractive for fish stocks. Also, analysis of satellite images showed a positive trend of upwelling frequencies both along the Swedish Coast of the Baltic Sea and the Finnish Coast of the Gulf of Finland.
Change of wind characteristics have caused alterations in the frequency and strength of upwelling events in the North Pacific area, especially in the Beaufort Sea, over the last decades. Intense shelf-basin exchange of water masses, which brings nutrient-rich waters to the Alaskan Beaufort Shelf, fuels primary productivity in this area. As a result of these events, the blooms of phytoplankton can be seen on satellite images nowadays. Surely, the abundance or availability of food (and the right type of food) become attractive to fish and other elements of the environment, and they migrate to new locations. According to recent data, inflowing warm and nutrient rich Atlantic water may cause high production in areas along the shelf breaks in the northern waters. This may particularly influence distribution and abundance of biological resources in the region.
No doubt, the effect of upwellings is complex and cannot be described as a single change in the entire Arctic region. Strength and direction of winds, as well as the topography of the coastline, may develop an extremely dynamic pattern of upwellings.
Fish stocks and future upwelling fisheries in the Arctic region
According to statistical data, coastal upwelling regions account for only 1 % of the ocean surface, but they contribute roughly 50 % of the world’s fisheries landings. Marine fisheries plays an important role in the Arctic and it includes various commercially important wild fish species. The entire area with intense fisheries (North-East Atlantic, Bering Sea, Central North Atlantic, and North-eastern Canada) allows to harvest up to 7.2 million tonnes of fish annually, which is about 10% of the global catch. Commercial fisheries attract local and international players in this industry, and are presumed to contribute significantly to economies of the Arctic states. Codfish, capelin, and herring are among the most abundant and most harvested marine fish species; they represent valuable fish stocks in the Arctic Ocean and adjacent seas.
Changing Arctic region, and especially growing upwelling areas, may dramatically alter established fisheries grounds and consequently bring new interests in the North. Understanding the role of upwellings as a result of climate change is crucial for many reasons. First, access to new areas with retreating sea ice and intensified upwelling effect, as well as alternated patterns in migratory characteristics of fish species, may potentially lead to rethinking of the commercial fisheries landscape in the Arctic Ocean and adjacent seas. Second, most likely it may also have a severe impact on traditional fisheries in the region as a result of changing environment and distribution shifts of marine organisms. Third, such dramatic changes may bring challenges not only to regional fisheries management but also to traditional practices in the Arctic region.
Ekaterina Uryupova is a senior fellow at the Arctic Institute. She is an environmental scientist who has worked in the polar regions as a researcher and guide. Her areas of expertise include climate change, marine ecosystems, fisheries and environmental policy.
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