Gelatinous zooplankton off the Northeast Greenland coast

Abstract

Gelatinous zooplankton are useful indicators of climate-driven shifts in the ocean; hence our study goal was to determine their diversity and distribution in the poorly investigated area of the Northeast Greenland shelf and adjacent waters. Zooplankton samples were collected vertically using a MultiNet in August and September 2017, at 9 stations along two transects: northern and southern. Eleven taxa were identified, of which Plotocnide borealis had the largest share within the assemblage in both transects. Gelatinous zooplankton biodiversity was the highest in the north. The local bathymetry and hydrology both shaped the distribution of the gelatinous zooplankton, leading to the emergence of three ecological groups: 1) taxa typically associated with, or found exclusively, in the intermediate, colder shelf waters (e.g. Plotocnide borealis); 2) organisms associated with higher temperatures and greater depths, mainly of the off-shelf waters (e.g. Aglantha digitale); 3) organisms whose distribution depended mainly on salinity and oxygen saturation (e.g. Aeginopsis laurentii). Additionally, A. digitale was associated with the presence of the warmer waters of Atlantic origin, the presence of which on both sides of the Fram Strait allowed to compare our findings with better studied gelatinous zooplankton from the West Spitsbergen Current, leading to the conclusion that the existent evidence of progressing Atlantification suggests that such impacts might also be expected off the Northeast Greenland coast.