Harbor porpoises, which had been eliminated for many decades from portions of Puget Sound, are making a big comeback.

Researchers think one of the reasons is the ongoing cleanup of industrial waste flowing into the water.

Aileen Jeffries, a research scientist with Pacific Biodiversity Institute who has pioneered the use of passive acoustic monitors for studying the porpoise, is leading a team of volunteers and biologists to learn more about the playful creatures.

(READ the AP story from Beaumont Enterprise)