Environment : Sifting Through the Wreckage of a Shattered Ecosystem : Oil spills, oil well fires, vast armies fighting over fragile deserts--nature has taken a beating in the Persian Gulf. With the war over, experts are ready to assess the damage.

Two satellite photographs on Michael D. Gwynne’s desk here illustrate the pitfalls facing anyone trying to appraise the environmental effects of the Persian Gulf War.

The first, taken in late January, shows the smoke plume from a burning Kuwaiti oil field--a great, narrow smudge stretching 190 miles across the Gulf itself, reaching well into Iran. The second was taken 24 hours later: The smoke is gone.

“It burned itself out,” said Gwynne, head of the Global Environment Monitoring System of the Nairobi-based U.N. Environmental Program and a key figure in what may become one of the largest environmental-impact surveys of all time.

The two photos, he said, suggest the range of questions that must be asked about the Kuwaiti oil fires alone: “What exactly is burning--tankers, storage tanks, wells? And what kind of wells? High-pressure wells that would burn until someone puts them out? Or low-pressure ones, which are most of Kuwait’s wells, which will go out by themselves? Because you want to focus on putting out the fires that will otherwise burn for years.”

With the fighting ended, an international body of scientists and technical experts will soon begin to determine how the war has affected an ecosystem lying at a significant crossroads of global biology and weather. About 35 species of migratory birds cross the region or stop to breed or feed. Regional weather, which could be altered by smoke, could affect the monsoon season as far away as West Africa.

Some studies will examine ecological impacts that went unnoticed or unconsidered in the pre-ground war period, when most environmental attention was focused on possible oil spills or fires. These include the disposal of trash, waste, machinery and potentially toxic effluent from the allied force of about 800,000 troops, all tramping around a desert environment that had never in history been more than sparsely populated.

Gwynne observed some of that during a survey trip to the Gulf region Feb. 3-18, after the appearance of an immense spill, which the allies said was deliberately loosed by Iraq and which Baghdad blamed on allied air strikes. At one stopover at the vast air base at Dhahran, Saudi Arabia, he said: “I never saw so much junk floating around in my life. Packing crates and material, cleaning solutions and solvents of all types, paint for camouflage, some of which we know is toxic. It was all contained, but it will all have to go somewhere.”

Gwynne asked the authorities about disposal techniques, but as was characteristic of such questions at the time, he said, “the inquiries didn’t solicit any information about that.”

Also of concern is the effect of military maneuvering and training. If Marines practiced amphibious assaults along the Gulf shore, as some reports indicated, they may have churned up vegetation and breeding zones. This could destabilize parts of the shore’s biological communities; that is a process that nature undertakes by itself, but man’s actions would tremendously accelerate it.

Still, as the smoke from the conflict clears, one thing is emerging: The scale of ecological damage may not be as great as initially feared.

The size of the major oil spill first detected on Jan. 19 has been continually overestimated. Initial figures placed its volume at 10 million to 15 million barrels, an exaggeration Gwynne ascribed to the possible misreading of satellite pictures as well as political inclinations among the allies to blame a worst-case scenario on Iraqi President Saddam Hussein. Current estimates are closer to 1 million barrels and probably less--although even that figure would make it close to four times the size of the Exxon Valdez oil spill in Alaska.

With much of the oil already being deposited on the western Gulf beaches between Kuwait and the Gulf of Bahrain, the question of what to do with it is rapidly becoming moot.

“Cleaning up can be disastrous,” Gwynne said. Trying to dredge oil out of the Gulf bottom would do more damage to vegetation and animal life than leaving the heavy tar in place, for instance. Gwynne recommended against such efforts once the oil comes ashore, although he said that “you should move heaven and Earth to keep it from coming ashore.”

As in any complicated ecosystem, every step has its benefits and dangers. “If you’re surveying a beach to judge where to put oil booms (to corral a spill), you might send birds into flight,” Gwynne said. “They head out to sea and end up in the oil. You may rescue 100 birds and frighten 500 others into the oil.”

As for perhaps the most familiar and highly publicized element of the cleanup--the washing of oil-covered sea birds--Gwynne questioned whether that effort has any point beyond a symbolic one. “You can wash the outside of them but not the inside.” A bird slathered in black crude has probably ingested enough of it to cause its death, however well its feathers have been scrubbed, he noted.

Conservation officials on the scene are already facing the problem of what to do with hundreds of cleaned-up birds now residing in pens on the ground. “If they’re released where there’s a lot of oil, they’ll be back in it in no time,” Gwynne said. Among the possible solutions is to ship them to the Red Sea, or to the Iranian side of the Gulf (which would require Iranian permission).

Another consideration that must be included in any assessment of environmental damage is the generally filthy state of much of the Gulf littoral zone to begin with. Members of Gwynne’s survey team repeatedly came across beaches covered in tar that was too old to have come from the latest spill and too new to have come from the previous great Gulf spill seven years ago during the Iran-Iraq War. “Some of the beaches look like Tarmac roads,” one British expert commented to Gwynne.

So far, scientists expect the major ecological damage to be local. In part this is a testament to nature’s resilience. “Ecosystems are tough, and they recover much more quickly than people think,” Gwynne said. “In the desert, where lack of water is a limiting factor in the growth of vegetation, it may take longer. But in the marine environment, the recovery of most of the littoral will be fairly quick.”

Few of the worst-case scenarios floated before the war began seem applicable now. Smoke from the Iraqi-set oil fires in Kuwait has not entered the upper atmosphere, a menace that might have inspired long-term and widespread meteorological changes. In fact, scientists quickly established that such fires would not be sufficiently hot or concentrated to send soot billowing to higher altitudes.

Moreover, the Gulf region is not an ecosystem of such far-reaching importance as, say, the rain forests of Brazil and Zaire or the hills of Madagascar, which nurture thousands of unique species.

That does not mean that isolated disasters may not take place. Saudi environmental officials are particularly concerned about the Socotra cormorant, a rare sea bird that uses the Gulf of Bahrain as a major breeding ground. Although this does not now appear likely, the January oil slick could conceivably reach that gulf just as breeding begins.

Also menaced in the Gulf of Bahrain are sea grass beds that not only shelter breeding grounds of some species of fish but also are the main food of dugongs, sea mammal cousins of the manatee. Their habits are so little known that estimates of their population range from 1,000 to 7,000.

* SADDAM’S WAR ON THE GULF: An illustrated look at the ecosystem. Page 6