Latitude, sea ice, and glaciers are important drivers of submerged vegetation distributions in the Arctic coastal waters along east Greenland

Abstract

Present study is the first quantitative and coherent presentation of the submerged marine vegetation along the Greenland east coast, from 65.5°N to 76.8°N, based on data obtained from 286 underwater video transects. Based on cluster analysis, four different marine submerged vegetation community figurations were identified: a southern and deeper kelp forest including Laminaria solidungula and Agarum clathratum, the marine vegetation along the Blosseville coast, seaweed meadows characterized by, e.g., submerged Fucus distichus, and high‐arctic kelp forest. The habitat figurations were related to and potentially explained by drivers considered to be key for their spatial distribution. The drivers considered were latitude as a proxy for light conditions with stronger seasonality and receding light conditions toward the north, suitable substratum for the marine vegetation to establish and grow, and the sea ice conditions with respect to light attenuation and scouring. Two of the vegetation types were explained by latitude, whereas the two vegetation types identified for the mid segment of the surveyed coastline were considered to be more correlated to local/regional conditions such as the presence of dynamic sea ice and glaciers as well as smaller‐sized hard substratum. Some degree of marine vegetation/kelp forest pauperization was observed with increasing latitude, expressed as a decrease in coverage and depth distribution. The vegetation belt was declining from a depth of 34 to 18 m within the northward latitudinal gradient surveyed, although for some species, no change in species‐specific maximal depth limits could be observed.