Antarctic waters are key to understanding climate and man-made effects on the rest of the planet. Though in the United States there often is ideologically based debate in the media and halls of Congress about whether or not global warming is a reality, Antarctic scientists are well beyond this. In some areas around the continent, Antarctic ice has been melting at high rates in recent years, creating concern over what this might mean for the environment and human activities there.
“One of the physical limits to krill fishery operation is the dynamics of sea ice,” says Dr. SoKawaguchi, a principal research scientist at the Australia Antarctic Division. “Changes in seasonal sea-ice cover, i.e. decrease in sea ice, may allow more access by the krill fishers to areas where, historically, there were no fishing activities during winter season, and this may have consequences for the ecosystem in particular to related and dependent species.”
In April 2011, researchers observed a huge aggregation of more than 300 humpback whales gorging on the largest swarm of Antarctic krill seen in more than 20 years in bays along the Western Antarctic Peninsula. The feast is happening in previously little-studied bays that are still largely ice-free deep into austral autumn, an unusual event, as winter sea ice used to cover much of the Antarctica peninsula’s bays and fjords by May, protecting krill and forcing humpback whales to migrate elsewhere to find food.
Scientists are surprised at how rapid climate change is affecting the region, and say that if the trend of melting sea ice continues, the humpbacks could diminish the krill biomass that is the food stock for many species in the Antarctic.