A mix of sea ice, polar desert, and open water habitats, the Greenland Sea ecoregion spans the length of the East Greenland Shelf. Covering approximately 1.2 million km2 and stretching over 20 degrees of latitude, this ecoregion is characterized by cold, nutrient-rich waters that support a diverse range of marine species including various seabirds, seals, whales, and fish, such as the Atlantic cod, Arctic char, and herring.
There are two distinct subregions in the Greenland Sea ecoregion- the north with cold, fresh polar waters, year-round sea ice, and little anthropogenic activity and the southern half with warmer, more saline waters, and seasonal drift ice.
Human activities
Fishing is the most important human activity in the ecoregion. The majority of commercial fisheries take place offshore in the southern half of the ecoregion which is an important fishing ground for several countries. Fishing pressure is generally close to levels to achieve maximum sustainable yield for commercially harvested stocks, with the exception of pelagic redfish. Fisheries also remain the most essential economic sector for Greenland.
Local communities here are dependent on inshore fishery and local hunting. Hunting affects several marine mammal species and has contributed to population declines in several species in the ecoregion. The abundance of the Greenland Sea hooded seal, harp seal, and narwhal populations remains at very low levels.
While this ecoregion does have fewer types of human activities compared to other ecoregions, it is a sink for contaminants and litter transported here from global sources outside the ecoregion.
Climate change
The Greenland Sea is strongly affected by climate change. From hydrography to marine mammals and birds, the ecoregion has and continues to experience environmental change, mostly as a result of far-field anthropogenic activity. The extent of both summer and winter sea ice has decreased over the past decades and there is evidence of changing surface water temperature and salinity, with pronounced sub-regional differences and consequences for the timing and intensity of stratification throughout the ecoregion. The extent of both summer and winter sea ice has decreased over the past decades.
These climate-induced modifications to the physical habitat have caused changes in the spatial distribution of several fish species, such as mackerel and bluefin tuna, marine mammals like humpback whales, and seabirds, such as common eider and great cormorant.
The impacts of climate change, overfishing, marine pollution, ocean acidification, and invasive species can have cascading effects on the entire ecosystem, including changes in the food web and reductions in biodiversity. It is essential to monitor and manage these impacts to ensure the sustainability of the Greenland Sea ecoregion and its important role in global ocean health.
Increasing data
ICES first published an ecosystem overview for the Greenland Sea ecoregion in 2020. At that time, Colin Stedmon, DTU Aqua and co-chair of the Working Group on Integrated Ecosystem Assessment of the Greenland Sea (WGIEAGS) said that it was difficult to provide an accurate assessment of change in the region as there was very little coordinated sustained data collection. "We have now used considerable effort in gathering data from different sources", says Stedmon, "The data analysis that has been done clearly shows that the oceanographic conditions are changing, and has consequences for the ecosystem. But as the UNDOS Arctic Action Plan emphasises there is still a need for systematic, coordinated sustained observations, if we are to have a situation where society can predict and adapt to the change underway."
Efforts have begun working in this direction. Not driven by WGIEAGS in particular but by international efforts, such as the drive to develop a distributed biological observatory in the Atlantic Arctic. Jesper Boje, DTU Aqua, Greenland Institute of Natural Resources, and co-chair of WGIEAGS, adds that "A generic focus on ecosystem monitoring has developed in recent years along with international requirements of ecosystem managing and fisheries certification".
ICES Northwestern Working Group (NWWG) and Working Group on Widely Distributed Stocks (WGWIDE) have also contributed with fisheries information on demersal and pelagic stocks in the ecoregion. More international projects on climate change impacts have provided information to the group, including the ECOTIP project.
The inclusion of results from several recent studies on oceanographic change are among some of the main revisions carried out, for example Sæs et al. 2022, Gjellstrup et al. 2022, and Heidie Jørgensen et al. 2022.
Overviews in use
Stedmon has presented this Overview at Arctic Frontiers and will present some findings at Mapping the Arctic conference in Nuuk next week.
Greenland fisheries management authorities use the overview as a basis for decisions on conservation issues. The fishing industry uses the advice as a basis for certification of fisheries in the area.
"The overviews are intended to be used by NEAFC for management purposes within its Convention Areas - the Greenland Sea is one of the many ecoregions in the NEAFC Convention Area", says Boje, "But the relatively new advice for this ecoregion and the data compilation behind the product is an extremely valuable product/database for other research institutes in the North Atlantic to achieve their research and advice objectives". ECOTIP provide information to WGIEAGS, but they are also continuously receiving output from WGIEAGS to reach their project objectives. Likewise, future projects on the ecosystem in the area will benefit from WGIEAGS work.
View and download the revised Greenland Sea Ecosystem Overview in ICES library.
*Updated on 23 April to include comments from Jesper Boje and Colin Stedmon.
