The study on invertebrate communities in East- and West-Greenland shelf waters was embedded in a fisheries survey carried out during the 379th expedition of the German fisheries vessel Walther Herwig III of the Thünen Institute of Sea Fisheries, Hamburg, Germany. The aim of the study was a coarse classification of the bycatch comprising macrobenthic organisms. On the one hand the marine ecosystem of this area provides food for commercially valuable fish stocks and plays, potentially an important role in the remineralisation of nutrients. On the other hand it experiences stress by traditional bottom trawling as well as anthropogenic and natural climate variability. As a consequence the study can provide a baseline to detect further changes in the composition of this component of a sub-arctic marine ecosystem.

Bottom water temperature measured by a sensor attached to the headrope of the trawl. Trawl distance was calculated using Meeus' great circle and WGS84. The opening of the commercial 140 ft. otter trawl was on average 20 m and the height 2.5 m. 21 inch-steel bobbins and rubber disks were attached to the footrope. The trawl had a mesh size (stretched) of 80 mm and of 20 mm in the cod end. Event 1 refers to the end of paying out the ropes and event 2 refers to the start of hauling up the trawl, assuming that the time in-between both events marks the period of efficient fishing.