The long search for ways to mop up offshore oil spills

The scene was incongruous enough: bulldozers and road graders on a stretch of white sand normally populated with beachcombers basking under a jalapeno-hot Texas sun.

But the continuing cleanup last week of an oil spill along the Gulf coast near Galveston was a grim reminder of the risks of living in the oil age.

Over the past decade, experts say, the United States has made big strides in being able to respond and help clean up after a spill. But no sure-fire method exists to contain, and defend against, a big spill or well blowout at sea.

New tricks are being devised - from oil-devouring bacteria to computer mapping - but the best weapon against an errant slick may still be a prevailing wind or current moving out to sea.

''There is no one panacea,'' says Carl Oppenheimer, a professor of marine studies at the University of Texas at Austin. ''We are moving some 3 to 4 billion gallons of oil and oil products every day somewhere on the earth's surface. We are going to make mistakes.''

One consoling fact may be that, until recently at least, the need to mop tanker spills and well blowouts was shrinking. Between 1979 and 1982 there was a steady drop, worldwide, in the amount of oil lost at sea and on land (the latter including such things as leaks from pipelines and storage tanks).

Indeed, the worldwide loss in 1982 of some 133 million gallons represented a 57 percent decrease from losses the year before, according to the Oil Spill Intelligence Report, a Cambridge, Mass., newsletter that tracks such trends. But that is changing. The tally for 1983, soon to be released, is expected to show a dramatic increase in oil losses over '82. This is largely due to a couple of major tanker spills and the continuing strife in the Persian Gulf.

The recent rupture of a British tanker in the Gulf of Mexico won't do anything to help the 1984 numbers. Although not a huge spill (it oozed 2.8 million gallons into the briny gulf, in contrast to 78 million spilled off the coast of South Africa last August), size isn't the key. It's where the crude ends up. The runaway residues from the hobbled Alvenus, as it turns out, probably won't cause major environmental damage. Winds and currents carried much of the gooey slick to a string of beaches northeast of Galveston, where crews are still working to cart it away. Bypassed were coastal wildlife refuges in Texas and Louisiana and several wetlands that serve as hatcheries for shrimp and fish.

But the battle against offshore accidents, as the latest one reminds, remains largely a defensive one: Wait until the oil washes up, and do the best to clean it up. The biggest improvement in handling oil spills over the past decade, in fact, may not be any marvel of technology, but teamwork. Cleanup crews and scientists, in the form of the Coast Guard's three regional strike teams and the National Oceanic and Atmospheric Administration's (NOAA) hazardous materials response team, now get to spill scenes quickly. Many states and towns have their own backup contingency plans and workers.

Yet some experts believe more detailed planning needs to be done, at the local level in particular, if spills are to be contained early. ''You need to know exactly who is going to respond,'' says Dr. Roy Hann, head of an oil-spill assistance team at Texas A&M University. ''You just can't do it as a last-minute decision.''

The physics of slicks is also becoming better known. NOAA's response team uses ocean current probes, aerial reconnaissance, computer modeling, and other high-tech tools to help chart and predict the flow of wayward oil at sea. Two NOAA oceanographers (''slickbusters'') were in Texas shortly after the tanker began spewing oil. They funneled information back to NOAA researchers in Seattle , who fed it into a computer containing data on everything from tides to water temperatures for most of the US coastline.

Still, little can be done to contain a large slick at sea. The approach is generally to set up booms, corral the pollutant, and then use skimmers and pumps to remove it. This works fine on rivers, lakes, and calm bays. But in rough seas , where a patch can roam at will, it is as tough as bottling a frog. The longer oil stays in water, moreover, the thicker it gets, befouling pumps. ''We just can't build a dam out there,'' says John Robinson, head of NOAA's hazardous materials team.

Better booms and absorbants that blot up oil have come along, but there's nothing revolutionary. Other weapons either being looked at or developed are:

* Chemicals. ''Dispersants'' are widely used in Europe and many other countries but have not been a regular part of the US arsenal. They can be effective: When sprayed on an oil patch, they break up the crude and reduce its damage-causing potential. The first chemicals used in the 1960s worked well but were highly toxic and, some argue, were more a threat to marine life than the oil itself.

More benign brews have been developed since then, but they require federal approval in the US as well as a special decision of the local response team at a scene. There are some practical problems, too. Large quantities have to be available and spirited in quickly: Once oil thickens, chemicals usually won't break it down.

* Bacteria. One other area of growing interest is oil-devouring bacteria. Microbes found naturally in the environment are used to clean up organic toxic wastes on land. But not much has been done in applying them to oil pollutants in marine environments. A few firms now believe technical solutions are at hand. One Texas start-up, Natural Hydrocarbon Elimination Corporation, expects to have a commercial product within six months.

The company has come up with mixtures of organisms that, it contends, will quickly consume oils (particularly lighter crudes) in different waters. In field tests, the bacteria disposed of a 20-gallon slick in less than four hours. Microbes are no magic potion for big spills, concedes Dr. Oppenheimer, a company consultant, but they may eventually be a potent tool.

Still, as Richard Golob, executive editor of the Oil Spill Report, notes, until something else comes along, the only sure way to deal with offshore accidents is another ounce or two of prevention: well-trained ship and oil-rig crews and better navigation systems.