Monnett 's research has been focused on the Arctic . He is the author of several studies on the Arctic ecosystem , particularly several done for the U.S. Fish and Wildlife Service in the wake of the Exxon Valdez oil spill Some of Monnett 's most noted work deals with polar bears and the effects of climate change on the species . Monnett was on a research flight tracking bowhead whales in 2004 when he and a colleague , Jeff Gleason , spotted four dead polar bears floating in the water after a storm . After additional research , Monnett found that this was " the first time dead bears had been spotted among more than 350 sightings of swimming bears recorded over 16 years of surveying the area . " Monnett conjectured that this was due to " bears having to swim up to 60 miles across open sea to find food . They were being forced into the long voyages because the ice floes from which they feed were melting , becoming smaller and drifting farther apart . " Monnett published his findings in 2006 in an article in the peer-reviewed journal '' Polar Biology '' . Al Gore referenced Monnett 's study in his 2006 documentary '' An Inconvenient Truth '' , which made the polar bears into an important symbol of climate change . The paper was cited by the U.S. Fish and Wildlife Service in its 2008 decision to list the polar bear as threatened under the Endangered Species Act
Exxon Valdez oil spill
Exxon Valdez oil spill
Charles Monnett