The loss of coastal sea ice and total sea ice extent has already had negative impacts and will have greater impacts on species that depend upon these habitats in the future. Walruses depend upon the ice to rest and to have their young, and as the ice retreats they will have to swim farther to the shallower areas of the ocean bottom that hold their food. Seals use the coastal ice to give birth on and nurse their pups there for six weeks, but with earlier breakups of the coastal ice this nursing period may be shortened, lowering their chances of survival. Meanwhile, polar bears have already been found to be sensitive to changing climate. They already have, and are likely to experience greater hazards due to: heat exhaustion, drowning due to swimming across large areas of open water between ice, and fewer months to feed in due to earlier breakup and later formation of near shore sea ice (9). Sea ice melt may have on many other marine organisms since “the food web of the Arctic Ocean relies in part on microscopic algae that grow in the sea ice” (3).

In the Antarctic, there are indications for changes in the future as well. The Marginal Ice Zone, a region of ice that covers the transition area between solid ice pack and the open ocean, may shift southward, and this change is important to Antarctic seabirds. Also, this area is important to the reproduction and recruitment of krill, and changes in it could result in shifts to other species, such as copepods and fish. This could have ocean-wide impacts on seabirds and other krill consumers (14).