Sea ice meiofauna distribution on local to pan-Arctic scales
Earth's ecosystems are networks where everything is connected. A decline in abundance of one species often affects the abundances of other species. Charismatic animals, such as polar bears and seals, are dependent on energy and nutrition supplied by small organisms such as microalgae and crustaceans. In the realm of polar bears and ringed seals, the sea ice, these lower trophic levels partly inhabit the tiny liquid-filled network of brine channels of Arctic sea ice. The older the sea ice, the more complex the structure, giving more room for diversity and abundance of sea ice inhibiting fauna and flora.
Sea ice extent in the Arctic Ocean has declined by over 30% since the satellite record began in 1979. The average age of individual Arctic ice floes has decreased from multiyear (surviving more than one summer) to mainly first- and second-year sea ice. Multiyear sea ice, which used to cover about 75% of the Arctic in 1983, is currently limited to the areas north of Greenland, the central Arctic, and parts of the Canadian Arctic Archipelago with as little as 62% of the summer ice cover remaining compared to 1978–1988 values. Dates of sea ice freeze-up and breakup have also shifted substantially, leaving large parts of the Arctic without sea ice for an increasing amount of time. Consequences for sea ice biota — from bacteria to polar bears — seem inevitable, but are largely undocumented.
A recent study published by researchers from the Norwegian Polar Institute, UiT The Arctic University of Norway and University Centre on Svalbard in Ecology and Evolution compiles the information about sea ice meiofauna, tiny creatures such as round and flat worms living inside brine channels in the Arctic sea ice. While there is still too little information to conclude much about the importance of these animals, the study asks to increase research effort on addressing the unknowns about these poorly studied animals. The study was compiled by the Sea Ice Biota Expert network in Conservation of Arctic Flora and Fauna, which was part of the State of the Arctic Marine Biodiversity Report.
Bodil A. Bluhm m.fl: Sea ice meiofauna distribution on local to pan-Arctic scales in Ecology and Evolution, 2018, 1-15.