Imprint of Climate Change on Pan-Arctic Marine Vegetation

• Published in: Frontiers in Marine Science
• Main Authors: Krause-Jensen, Dorte, Archambault, Philippe, Assis, Jorge, Bartsch, Inka, Bischof, Kai, Filbee-Dexter, Karen, Dunton, Kenneth H., Maximova, Olga, Ragnarsdóttir, Sunna Björk, Sejr, Mikael K., Simakova, Uliana, Spiridonov, Vassily, Wegeberg, Susse, Winding, Mie H.S., Duarte, Carlos M.
• Other Authors: Biological and Environmental Science and Engineering (BESE) Division, Marine Science Program, Red Sea Research Center (RSRC), Arctic Research Centre, Aarhus University, Århus, Denmark, Department of Bioscience, Aarhus University, Silkeborg, Denmark, ArcticNet, Québec-Océan, Université Laval, Québec, QC, Canada, Centre of Marine Sciences, University of Algarve, Faro, Portugal, Alfred-Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, Department of Marine Botany, Faculty of Biology/Chemistry and MARUM, University of Bremen, Bremen, Germany, Institute of Marine Research, His, Norway, Marine Science Institute, University of Texas at Austin, Port Aransas, TX, United States, Shirshov Institute of Oceanology, Moscow, Russia, Icelandic Institute of Natural History, Akureyri, Iceland, Department of Bioscience, Aarhus University, Roskilde, Denmark, Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Frontiers Media SA 2021
• Subjects: Arctic; Canada; Greenland; Norway; Svalbard; Climate change; Iceland; Sea ice; Alaska
• Online Access: http://hdl.handle.net/10754/666913; https://doi.org/10.3389/fmars.2020.617324

The Arctic climate is changing rapidly. The warming and resultant longer open water periods suggest a potential for expansion of marine vegetation along the vast Arctic coastline. We compiled and reviewed the scattered time series on Arctic marine vegetation and explored trends for macroalgae and eelgrass (Zostera marina). We identified a total of 38 sites, distributed between Arctic coastal regions in Alaska, Canada, Greenland, Iceland, Norway/Svalbard, and Russia, having time series extending into the 21st Century. The majority of these exhibited increase in abundance, productivity or species richness, and/or expansion of geographical distribution limits, several time series showed no significant trend. Only four time series displayed a negative trend, largely due to urchin grazing or increased turbidity. Overall, the observations support with medium confidence (i.e., 5–8 in 10 chance of being correct, adopting the IPCC confidence scale) the prediction that macrophytes are expanding in the Arctic. Species distribution modeling was challenged by limited observations and lack of information on substrate, but suggested a current (2000–2017) potential pan-Arctic macroalgal distribution area of 820.000 km2 (145.000 km2 intertidal, 675.000 km2 subtidal), representing an increase of about 30% for subtidal- and 6% for intertidal macroalgae since 1940–1950, and associated polar migration rates averaging 18–23 km decade–1. Adjusting the potential macroalgal distribution area by the fraction of shores represented by cliffs halves the estimate (412,634 km2). Warming and reduced sea ice cover along the Arctic coastlines are expected to stimulate further expansion of marine vegetation from boreal latitudes. The changes likely affect the functioning of coastal Arctic ecosystems because of the vegetation’s roles as habitat, and for carbon and nutrient cycling and storage. We encourage a pan-Arctic science- and management agenda to incorporate marine vegetation into a coherent understanding of Arctic changes by quantifying ...