Washington -- A U.S. report says melting Arctic sea ice could reduce the world's polar bear population by two-thirds within 50 years.

The U.S. Geological Survey said the sea ice that polar bears depend on as a platform to hunt seals, which is their primary food, is decreasing throughout their Arctic range due to climate change. Models used by the USGS team project a 42 percent loss of optimal polar bear habitat from the Polar Basin during summer by the middle of this century, the agency said Friday in a release.

Wildlife officials are considering whether to list the polar bear as a threatened species under the Endangered Species Act.

--
Copyright 2007 by United Press International.