The water in the northern area of the ecoregion has warmed and become more saline over the last two decades. Surface waters on the narrow southeastern Greenland shelf and in the area north of Denmark Strait are 1–2°C warmer than the mean conditions for 1981–2010 for much of the year (Figure 8). In contrast, surface waters in the southeastern reaches of the region have cooled by up to 2°C. Surface salinity has increased in the open waters of the ecoregion, but decreased in the East Greenland shelf waters and Irminger Sea surface waters.
The sea ice coverage in the ecoregion has been diminishing over several decades (Figure 9). The winter maximum sea ice extent has generally decreased since satellite records began in 1979, while a small decline in summer minimum ice coverage has been seen from 2006 onwards. Retreating sea ice has been linked to the increasing occurrence of migratory whale species such as finwhales and humpback whales on the East Greenland shelf.
Bluefin tuna has been observed in the ecoregion since 2012. The seasonal occurrence of bluefin tuna is associated with warming sea surface temperatures in the southern subregion and associated increase in prey availability, namely Atlantic mackerel immigration to the area.
There is evidence of northward shifts in some breeding populations of seabirds in East Greenland, including the immigration of at least two bird species to the southeastern part of the ecoregion in recent decades: great cormorant and lesser black-backed gull. The breeding areas of common eider have also expanded more than 200 km northwards.
Climate model comparison studies indicate that from 2000 to 2050, the maximum fish catch potential in the region will increase by 25% under both low (RCP [Representative Concentration Pathway] 2.6) and high (RCP 8.5) CO2 emission scenarios. This is globally unique and in strong contrast to maximum fish catch potential at lower latitudes (south of approximately 60°N), which are expected to show the opposite trend.
There has been a persistent westward shift in capelin distribution since the late 1990s and early 2000s, from the Icelandic Waters and Norwegian Sea ecoregions to the Greenland Sea ecoregion. Most of the nursery grounds for juveniles have moved to the southern subregion. The summer feeding grounds for adult capelin are now mainly located in the northern subregion. In addition, several boreal species such as Atlantic cod, beaked redfish and deep-sea shrimp recently found on the Northeast Greenland shelf originate from the Barents Sea. These changes are thought to be a response to large-scale ocean climate changes as a result of global warming.
Figure 9: Monthly average sea ice extent for the Greenland region (Meier et al., 2007), which corresponds to an area covering the Greenland Sea, Icelandic Waters, and the western part of the Norwegian Sea ICES ecoregions.
Figure 8: Temperature and salinity anomalies for surface waters of the North Atlantic region reported by ICES Working Group on Oceanic Hydrography. Anomalies are calculated as differences between monthly means (Argo data) and World Ocean Atlas 2005 climatology. Top maps (red and blue): temperature; bottom maps (brown and green): salinity (Gonzalez-Pola et al., 2019).