Site: Palmer Antarctica LTER

Credit: PAL LTER

Shifts in sea ice are affecting the WAP ecosystem and biogeochemistry. Despite dramatic shifts in Antarctic food webs, the number of the keystone krill species (Euphausia superba) has not changed significantly over the PAL LTER study area. However, researchers have observed reduced juvenile recruitment following positive anomalies of the Southern Annular Mode. North of PAL LTER, E. superba population centers in the southwest Atlantic sector have been contracting southward for the past 90 years.