CRAWDADS crawl and killdeer call again less than a year and half after 440,000 gallons of oil spilled into an intricately sensitive marshland here. ``It's not totally OK, but I would say it's 90 percent back,'' says Richard Bogaert, the biologist who monitors the 120-acre wetlands. ``The marsh shrubs and grasses seem to have grown back, coming up from the roots. And we've had good nesting this year: pintail ducks, mallards, cinnamon teals.''
The remarkable recovery had its price. It took 14 months and cost Shell Oil Company $12 million, nearly $30 for each gallon spilled. A small part of that money was paid to fishermen, but most was spent on labor-intensive oil cleanup, according to Bill Sharkey, community relations manager for Shell.
This success doesn't necessarily inspire hope about the thousands of oil spills reported to the Coast Guard each year, including the 11 million gallons that coated 9,600 square miles of Alaskan waters and shoreline in late March. Each spill is different.
Mike Rugg, a water-quality biologist who was the state's overseer at the Martinez cleanup, is hesitant to draw comparisons between the Alaskan spill and the Martinez marsh.
``The amount was so different up there and conditions are so different,'' he says. ``You've got open ocean there and the arctic weather. And the equipment that we used was not available there.''
The Martinez wetland's thick stands of cattails and acres of dusty green pickleweed were cleaned manually, square foot by square foot. Twenty-person crews of contract laborers worked 40 hours a week for six months. They sought out oiled plants and trimmed them down to ground level, trying not to disturb their roots.
``The marsh is like tundra in that human footprints damage it,'' Mr. Bogaert says. ``That opens up the area for annual grasses and weeds that replace the marsh habitat. The marsh's grasses and shrubs are perennials and take longer to get established. They're battling it out right now in some areas.''
The wetland is unusual in that its pre-spill condition was well documented. The marsh has been maintained by the Mountain View Sanitary District since 1984 to provide habitat for migratory birds and other creatures that need the now-scarce wetlands.
Bogaert, who works for the district, has observed waterfowl and analyzed water nutrients at this marsh and another owned by the district for eight years. He had completed his spring bird census just days before the flood of heavy crude oil started down Peyton Slough toward the marsh on April 22 last year. A drainpipe in a 12-million-gallon storage tank at the Shell refinery a quarter-mile away had ruptured, and a safety valve that was supposed to be closed was open.
In much of the marsh and the slough, Bogaert says, the oil was a black carpet about four inches thick, suffocating everything in its path, down to the bacteria. Hundreds of birds died.
Early on, the spill managers decided to sacrifice the wetlands, hoping to contain the spill and prevent further damage downstream. Workers dammed the odd little wildlife oasis, which is sandwiched between an interstate freeway and a railroad line. It became a holding pond for the tide of poison.
``About half the oil was recovered from the marsh and Peyton Slough,'' says Mr. Rugg, who works for California's Department of Fish and Game. The remainder was distributed downstream in the slough and in the nearby open waters of Carquinez Strait and Suisun Bay.
The oil tainted other wetlands, although less severely than the district's marsh, and fouled some rocky intertidal zones.
``Altogether,'' Rugg says, ``about 50 miles of coastline were affected to one degree or another. About five to eight miles were severely affected.''
Rugg, whose job is to make sure that cleanups comply with state requirements, has worked in the aftermath of about 20 major oil spills since 1970 in San Francisco Bay. He says that each spill requires a decision on how aggressively to respond. ``We have to take into account the residual damage from the cleanup itself.''
In a marsh, he says, ``Foot traffic can drive the oil into the substrate. That damages the root structure and can result in more loss of habitat and vegetation than just leaving the oil there.
``The oil companies, in general, have taken the position that oil, being a biodegradable material, will break down in time and any cleanup in the fragile areas will cause more damage than benefits.''
Rugg recognizes some merit in that position, he says, ``but in this case, we had endangered species and migratory birds using these wetlands. The potential effect of oiling on these birds was so severe that immediate cleanup and removal of the oil was prudent.''
In the first stage of the cleanup, as much oil as possible was vacuumed off by trucks at the marsh's edge.
From there, the wetlands crews had to step more lightly. The marsh was drained to harden the top layer of soil, so walking on it wouldn't damage roots. Drying out the marsh didn't hurt it, because wetlands are seasonal and dry up in summer under normal circumstances.
After the earth was firm, around mid-June, laborers began mowing down the oil-fouled salt grass, spike rush, and alkali heath with hand-held weed-cutting tools. They bagged the cuttings and carried them out on their backs.
``They had the whole marsh marked off with little stakes and flags,'' says Bogaert. The root systems of the perennials survived for the most part. And with the wetland's reflooding this fall and winter, the marsh re-created itself.
Bogaert is still concerned with the oil's long-term effects in the nearby waters, where cleanup couldn't be so thorough. ``This spill has been cleaned up. But that's not the end of its impact,'' he says. ``The effects show up in the reproductive cycles of marine animals: with lower fertilization success, lower embryo survival rates, lower larvae survival.''
But any of that, he says, will be hard to blame on one spill.
``The oil got so dispersed that it will be difficult to find effects that stand out from the background pollution - from the tanker traffic, the refineries, and the industrial traffic.''
In the course of this and other cleanups, Rugg has come across areas tainted by old residues of oil spills. They form a tarlike surface over the shoreline, he says: ``It never recovers.''
In contrast, he says, at the marsh and in the rocky areas cleaned after the Shell spill, laborers carefully removed as much oil as possible and then allowed nature to work. ``What we learned from this spill,'' Rugg says, ``was that if you can effectively remove the oil, recovery is almost immediate.''
But the cost is already tremendous and rising, as the result of stiffer fines, tougher environmental standards, and escalating costs of equipment and specialized supplies. Exxon estimates it will spend $1.28 billion for its Alaska cleanup operation, or about $100 a gallon.