Biotic components - Articles
Expected increased temperatures related to climate change will likely affect growth rates and other biological processes. This may cause competitive conditions to change between cold-adapted bacteria and bacteria adapted to warmer waters (Børsheim and Drinkwater 2014). Consequently, the species composition of bacterial communities may also change as temperatures change.
Harp seals are migratory and have a much wider distribution range than ringed seals, bearded seals, and walruses; they also have a more pelagic life history (Lavigne and Kovacs, 1988; Haug et al., 1994a). Three different populations inhabit the North Atlantic: the Northwest Atlantic population off Canada’s east coast; the Greenland Sea (West-Ice) population which breeds and moults just north of Jan Mayen; and the East-Ice population which congregate in the White Sea to breed.
Hooded seals form one stock in the Northwest Atlantic and another in the Northeast Atlantic; although, recent genetic studies suggest no biological distinction between the groups (Coltman et al., 2007). In the Northeast Atlantic, whelping takes place in mid-late March in the West Ice, not far from where the West-Ice harp seals give birth. Between breeding and the moult, hooded seals carry out feeding excursions to the continental shelf edge off the Faroe Islands and Northern Ireland and to areas in the Norwegian Sea.
Among the toothed whales, the long-finned pilot whale, sperm whale, the northern bottlenose whale, and killer whales are summer visitors to the Barents Sea. The Northeast Atlantic population of long-finned pilot whales number some 780,000 individuals (NAMMCO 1998), but only a very small (and unknown) part of this population enters the Barents Sea. Few sightings have been made in areas covered by IMR surveys; these sightings are insufficient to estimate
Numbers of seabirds breeding in the Barents Sea Region have changed dramatically over the last 50 years. A recent assessment of population status and trends has been conducted, based on monitoring and census date for several species breeding in the western part of the Barents Sea (i.e., Norwegian mainland and Svalbard) (Fauchald et al., 2015). Resulting analyses indicate that breeding populations of subarctic pelagic auk species (common guillemot Uria aalge, razorbill
Future higher temperatures in the Norwegian Arctic, including the Barents Sea, will likely cause several pathogens (parasites, bacteria, viruses) to extend their distributions northward (Tryland et al., 2009). The prevalence and abundance of pathogens may also change. Such a change in distribution of pathogens may have several consequences for both wild and domesticated animals, which are difficult to predict due to a lack of data.
Several seabird populations in the Barents Sea region are of international importance. The most numerous species are: Brünnich´s guillemot (Uria lomvia); little auk (Alle alle); Atlantic puffin (Fratercula arctica); black-legged kittiwake (Rissa tridactyla), northern fulmar (Fulmarus glacialis); and common eider (Somateria mollissima). An important part of the global breeding population of the rare ivory gull (Pagophila eburnea) is found within the northern part of the region — in Svalbard and Franz Josef Land.
The Barents Sea is inhabited by 21 species of sea mammals. Among these, 11 species are threatened according to the IUCN Red List, 13 are included in the Red Book of the Russian Federation (2001) and 8 extant species are on the endangered species list of Norway (Table 4.3.6) (plus the recently extinct northern right whale stock). Anthropogenic factors thought to be most harmful for marine mammals are fisheries interactions, pollution, and climate warming; the
The Barents Sea region is inhabited by 28 fish species which are either on the Global Red List (8 species) or on the Norwegian Red List (25 species) (Table 4.3.6). Among these, 13 are data deficient (DD) species, i.e. the species would likely appear on the red list if adequate information were available. When considering the lists of rare and threatened marine fish species, 3 main groups of impact factors may be considered: 1) fisheries (catch and by-catch); 2) environmental
During the last half century, 2 major crab species were introduced to the Barents Sea: red king crab Paralithodes camtschaticus in the 1960s; and snow crab Chionoecetes opilio in the 1990s. Early this century(2000), species from the southern boreal areas have expanded northward to appear in the Barents Sea, including the snake pipefish Entelurus aequoreus, snail ray Dipturus linteus, whiting Merlangius merlangus, grey gurnard Eutrigla gurnardus, and megrim Lepidorhombus whiffiagonis.