Mesozooplankton abundance (0-100 m) of selected taxa in the Greenland Sea in August-September 2017

Mesozooplankton samples were collected in the Greenland Sea from 22 August to 12 September 2017, onboard RV Dana. Depth-stratified zooplankton samples were collected using a 0.25-m2 aperture Hydrobios MultiNet®, a sampler equipped with five 50-μm mesh nets (hereafter referred to as multinet). The multinet was hauled vertically from a depth of 1000 m or 10 m above the seafloor to the surface at a speed of 0.5 m s-1 and generally sampled in the following depth intervals: bottom-200m, 200-100m, 100-50m, 50m-surface. Samples were immediately preserved in a solution of 4% formaldehyde borax-buffered seawater. Known aliquots were taken using a Folsom splitter, and approximately 400-600 animals were enumerated, measured, and identified to species or to the lowest taxonomic level attainable. For copepods, stage and sex were also determined. Calanus hyperboreus were identified to species for copepodite stages C3-C6, while C. finmarchicus and C. glacialis were identified to species for C5 and C6 based on prosome length. Younger stages of Calanus were identified to genus only. Prosome lengths were measured for 10 individuals of each taxon and stage in each sample. Abundance of selected taxa (ind. m-2) were integrated over the first 100 m of the water column.