Andrew Derocher is a biologist at the University of Alberta who has researched polar bears for more than three decades. He is also a volunteer adviser to Polar Bears International, a conservation group.

He discussed the status of polar bears in the Arctic amid a warming climate, and the potential impact of oil and gas exploration. The interview has been edited for length and clarity.

Q. Worldwide in the Arctic, there are roughly 25,000 polar bears in what scientists consider to be 19 subpopulations. Over all, how are they doing?

A. People assume that because we’re concerned about polar bears from a conservation and management perspective, that all polar bears must be doing terribly. That’s not the case. Polar bears are doing just fine in many parts of their distribution, and with 19 different populations around the Arctic, we have 19 different scenarios playing out.