Small change in the environment, big impact on Arctic animal and human communities
Within the framework of my PhD I went onboard of the Research Vessel Helmer Hansen in the Greenland Sea (Eastern coast of Greenland), in collaboration with the Arctic University of Tromsø (Norway). The objective was to research seals distribution during breeding season. In order to look for seals three people use binocular on the right, center and left side of the vessel’s bridge. The geographic range is selected based on previous years. Usually breeding layers are constituted by large areas of ice packs which concentrate a great amount of seals. These areas move daily in a southward direction following the north-south circulation pattern. While in 2017 it has been relatively easy to find the breeding areas of seals, in 2018 it took much more time. First, the ice-packs were distributed in a more patchy way and, in addition to move southward, they would also move in a circular way. When we finally found the seals we were just 70km away from the Greenland coast. In 2017 the sea-ice edge was located at around 200km away from the Greenland coast. Between 2017 and 2018 around 100km of ice had disappeared. While it is normal to have large interannual variation of sea-ice concentration, the crew captain said that in 20 years of sailing in the area he was never so close to the Greenlandic continent. The changes in environmental conditions can affect the entire local marine food web from phytoplankton to top predators, concerning their biomass but also distribution. This might have large consequences to indigenous communities which rely heavily on sea products as main food sources.
Photo of breeding layers of hooded and harp seals on the ice packs in the Greenland Sea (in front of the Liverpool coast). photo credit: @ Leo Rescia
Written by Marianna Pinzone