Polar bears are completely dependent upon the Arctic sea ice for their survival. Unlike other marine mammals, polar bears cannot hunt, breed, or nurture their young in the water, and unlike other terrestrial carnivores, they cannot hunt efficiently on land. Polar bears make a living traversing the frozen ocean, and their life history patterns are coupled to the dynamics of both seasonal and perennial Arctic sea ice. Ultimately, it is important to understand that without Arctic sea ice, there would be no polar bears.
I was stunned by the recent news released by the National Snow and Ice Data Center. This organization uses passive microwave data from the Defense Meteorological Satellite Program to map the extent and volume of sea ice in both the Arctic and Antarctic. These data collection and analysis methods were developed by NASA and provide an incredible daily snapshot of sea ice conditions and makes these data accessible to the public via their website. The Arctic sea ice extent had hit a record low for this time of year. In 2007, Arctic sea ice hit an all-time low, and the current sea ice extent for 2012 is on pace to set a new record. This is not good news for polar bears.
The dynamic nature of the Arctic sea ice means that a number of oceanic and climatic factors may change sea ice dynamics for this year, but we cannot count on those factors lining up in such a way; we must act. We must reduce our carbon footprint. We must reduce our use of carbon-based fuels in order to reverse the trend toward a warmer climate. We must make these changes in order to preserve the Arctic sea ice so that, for millennia to come, polar bears will continue to roam the great frozen North.
Here at the San Diego Zoo, and with the research collaboration of Polar Bears International, we are committed to polar bears and polar bear conservation. While we wait to see (in great anticipation!) if Chinook will have cubs this year, we hope that Zoo visitors will continue to step up and reduce their carbon footprint. So, as we move into the summer months, get outside and ride your bike, turn off the TV, relax and read a book: any of these activities is good news for polar bears!