Wildlife biologists in Alaska are concerned about the decline in harbor seal numbers at Glacier Bay National Park. In an ongoing study they are capturing seals to take biological samples and implant transmitters that, hopefully, will shed some light on why the overall population has been dropping.

Factors that could be influencing the harbor seals' longevity include climate change that is warming the sea waters and affecting the food chain, as well as predation by killer, or orca, whales and even Stellar sea lions. Or, are the population dynamics simply part of the natural cycle?

This 7-minute video explores the population decline and examines what research is being done. Working on the project are the National Park Service, the Alaska Department of Fish and Game, the Hoonah Indian Association, and the Alaska SeaLife Center.