Emergency crews responded to another mystery oil spill in Puget Sound's Dalco Passage yesterday, just as state lawmakers were meeting to consider new spill-response guidelines recommended after a 1,000-gallon spill there last fall.

Reported about 11:20 a.m. by the Washington state ferry Rhododendron, yesterday's spill was thought to be a few hundred gallons of oil and appeared significantly less syrupy and dense than the Oct. 14 spill in the same area, said Coast Guard Petty Officer Mike Zolzer.

"It's very, very thin stuff that often looks a whole lot worse than it is, though I don't want to downplay this because we're still investigating it," said Sandy Howard, state Department of Ecology (DOE) spokeswoman. Thinner sheens are frequently less damaging than thick sludge or crude oil, she said.

The Coast Guard is trying to determine the source of yesterday's spill.

Helicopter spotters noted silvery sheens in Gig Harbor stretching through the Tacoma Narrows, along the western shore of Maury Island's Quartermaster Harbor, and a patch midway between Point Defiance in Tacoma and Vashon Island. Oil also was seen in Commencement Bay.

Late in the day, state and Coast Guard officials said none of the oil had reached shore, though TV footage seemed to indicate some was lapping against beaches near Commencement Bay.

By nightfall, the Coast Guard, state officials and two oil-response contracting crews were still on the water, working with an oil-skimming boat and containment boom designed to corral petroleum. However, officials believed much of the oil was unrecoverable.

"It does appear that there is boom being deployed at least around Dockton," on Maury Island near the mouth of Quartermaster Harbor, island resident Marnie Jones said.

Amid the response yesterday, the state House Natural Resources, Ecology and Parks Committee was listening to recommendations to improve how quickly and effectively the state and federal government attack oil spills. After a six-hour delay in response to last fall's spill, oil spread along 21 miles of beaches.

"The major concern I had after the first spill was response time," said State Rep. Joe McDermott, D-Seattle, who represents Maury and Vashon residents. "But from everything I've heard thus far, it was a very different response this time."

Kathy Fletcher, executive director of People for Puget Sound, said the October spill had put the agencies on alert, and "they knew they couldn't ignore this report."

"That last spill was a wake-up call, and this time they're definitely awake," she said. "Of course the last spill was just in October. What about a year from now?"

Fletcher and environmental activist Fred Felleman also asked if enough was being done to prevent spills, which each said appeared to be occurring more frequently. "Why are we continuing to have these spills?" Fletcher said. "Is there some failure somewhere?"

Yesterday's spill was eerily similar in some ways to the October spill. The locations were nearly identical, and both were reported by passing boats. Most spills are reported by those who cause them. State and Coast Guard investigators also immediately took spill samples to help identify the source.

The Coast Guard in December said tests linked the October spill to the Polar Texas, an oil tanker owned by a subsidiary of ConocoPhillips. ConocoPhillips disputes the claim.

Craig Welch: 206-464-2093 or cwelch@seattletimes.com