Spill Taints Upper Bay, Endangering Wildlife : Environment: Officials estimate 100 gallons of motor oil was dumped into a storm drain on Bristol Street. State starts cleanup.

The clandestine dumping of used motor oil into a storm drain has tainted part of Upper Newport Bay, threatening bird life and triggering a cleanup effort by the state Department of Fish and Game.

The oil entered the Upper Newport Bay Ecological Reserve, where salt marshes are home to hundreds of birds, including some rare species. While state officials cannot yet say what damage the spill might cause, they estimate that as many as 200 to 300 birds might come into contact with the oil.

“It happened to hit a very delicate habitat, with a lot of birds in it,” said John Grant, environmental specialist at the department’s office of oil spill prevention and response.

Workers on Tuesday captured four oil-tainted birds, and a fifth bird, a Western grebe, was found dead. Rescue efforts are continuing.

Officials think about 100 gallons of automotive oil was dumped late Sunday or early Monday into a storm drain behind a commercial plaza on Bristol Street.

Three 55-gallon drums were found at the site and investigators suspect that a so-called “midnight dumper” was trying to get rid of the oil.

“People do this senseless stuff to save themselves a buck,” Grant said. “This is a willful act on somebody’s part that totally ignored the consequences.”

The oil flowed through a channel into Upper Newport Bay, where it was spotted Monday morning and reported to state authorities.

Rescue teams are working to capture more oil-tainted birds and take them to a local veterinary center for treatment. Workers also are cutting oiled vegetation and using absorbent pads and booms to soak up the mess.

The cleanup price tag could top $20,000, not including the costs of treating the birds. Since the dumper is unknown, this is considered an “orphan spill” with the state bearing the costs, Patrol Lt. Mark Caywood of the oil spill prevention office said.

The spill is worrying wildlife experts in part because Newport Bay is home to the light-footed clapper rail, a rare bird that is listed as endangered by the federal government.

Most clapper rails are found in just a few coastal wetlands in the region.

“For wetlands and sensitivity, it would be hard to find a more sensitive spot than that in Southern California,” Caywood said.

Lubrication oil can hurt waterfowl by removing some of their natural thermal protective coating. When they preen their feathers, the birds ingest the oil, which can poison them.