BELLINGHAM, Wash. - Marine bird populations in northern Puget Sound have seen significant declines since the late 1970s, according to a Western Washington University study.

The four-year study included a census of 80 north Puget Sound marine bird species _ those that live in the water, not just the shores. Students gathered data from about 150 sites between Tsawwassen, British Columbia, and Whidbey Island.

John Bower, a professor of field biology at Western, says he's still working on the final report but that early results point to steep declines in a number of key species.

Among them: the common murre, a long-billed black and white seabird, whose population has declined 93 percent since the 1970s census; and the Western grebe, a long-necked black and white seabird, which has seen its numbers drop 81 percent.

Other birds in decline include the brant, a coastal goose common on Padilla Bay, and the scoter, a sea duck that's a popular catch for hunters.

Bower's study compares the latest numbers with data collected between 1978 and 1979, when the construction of oil refineries in the region prompted the federal government to document marine species in the area that could be harmed by an oil spill.

"It was perfectly normal to go out to the bay and see several thousand Western grebes on the shores," Bower said. But the recent study found a one-day average of 10 Western grebes on Padilla Bay and 436 on Bellingham Bay, Bower said. Now "they just aren't around," he said.

The study seems to confirm earlier results from bird counts by the state Department of Fish and Wildlife, but this time the birds were counted from the ground, not in the air.

David Nysewander, a Fish and Wildlife project leader who assesses marine birds on Puget Sound, said he wasn't surprised by the study results, but he says a lack of money prevents his department from doing much about it.

Bower said water pollution, eel grass destruction, global warming and habitat loss could all be factors in the bird decline, but he doesn't have the research to back that up.

In addition to government restrictions on shoreline development, he said individuals can do a lot to help the birds by limiting pollution and not allowing their dogs to disturb birds when walking on beaches.

By protecting the region's marine birds, Bower said, the public will be protecting the whole Puget Sound.

"If we have declines in the birds, it means the ecosystem that supports those birds is in trouble," he added.