PORTLAND — The killer foam that hit Northwest seabirds has subsided but conservationists are worried about a death toll they say numbers in the thousands.

University of Washington marine biologist and seabird specialist Julia Parrish says more than 10,000 scoters, or seaducks, were killed by the first algal foam that hit Washington's Olympic Peninsula in mid-September. She says that total amounts to 5 percent to 7 percent of their overall population on the West Coast.

She thinks thousands more seabirds, including many red-throated loons, were killed in the second wave of foam off southwest Washington's Long Beach Peninsula about two weeks ago.

The foam has been linked to the bloom of a single-cell phytoplankton, or algae, that hasn't posed a problem in the Northwest — until now. Winds blew the bloom toward shore where it was whipped by the surf into sticky foam that stripped the birds of their waterproofing.

There is some good news; several hundred rescued birds are being released.