SACRAMENTO (AP) -- The coho salmon, a bellwether of environmental health, could become extinct in California unless aggressive steps are taken to protect streams from logging in the North Coast, scientists said Thursday.

The fish is protected under the Endangered Species Act, but a controversial provision of the $500 million Headwaters Agreement creates an exemption for Pacific Lumber Co.

Under the deal, which set aside as a public preserve 7,500 acres of ancient redwoods owned by Pacific Lumber, the company has to apply for an ``incidental take'' permit in order to log on its remaining 200,000 acres. The permit would allow logging even if it resulted in the destruction of some of the 36 federally protected species on the land.

Scientists held a news conference to criticize Pacific Lumber's permit application, called the Habitat Conservation Plan. They said the plan includes some sound scientific information, but arrives at faulty conclusions aimed at increasing profits for the Scotia-based company.

``The embarrassment is not in the science. The embarrassment is in the inability to cope with a company who has no regard for the environment,'' said Dr. Michael Fry, a wildlife biologist at the University of California-Davis.