Pioneer aquanaut: How not to clean up an oil spill

Marine biologist, seabed explorer and former top US government scientist Sylvia Earle tells Phil McKenna how she helped to change George W. Bush's mind - and why she is angry about the methods being used to clean up the Gulf oil spill

LEANING towards me so as not to disturb other guests, Sylvia Earle shouts in a barely controlled stage whisper: "I just want to hit someone." We are waiting to be seated for breakfast at a swanky New York hotel overlooking Central Park. Later in the day, Earle will address a sell-out crowd at the city's annual World Science Festival, but at the moment she has other things on her mind. Staring at a picture of an oil-covered pelican on the front page of the day's paper, she is angry. "It's not their fault. They don't deserve this," she says.

What's upsetting her is, of course, the uncontrolled flow of oil into the Gulf of Mexico from the well drilled by the wrecked Deepwater Horizon rig. Given her lifelong devotion to the study and conservation of the seas, it isn't hard to see why.

In 1970, not long after astronauts first walked on the moon, Earle led a team of all-female "aquanauts" - a mixed team was deemed too controversial - to live for two weeks in an enclosed habitat on the ocean floor, conducting studies of seabed life. Earle has lived under water on nine different occasions and has logged nearly 7000 hours under the surface, including a 1979 solo walk on the sea floor 380 metres down without a tether to the surface. This earned her the record, still unsurpassed, for the deepest untethered dive not in a submersible, as well as the title "Her Royal Deepness".

Other accolades include the species named after her, including the sea urchin Diadema sylvie and Padina earlei, a fan-shaped brown alga. But today Earle's thoughts are consumed by the ecosystems affected by the spill. Frustratingly, she has seen it all before. In 1989 she saw first-hand the catastrophic effects of spilt oil after the supertanker Exxon Valdez ran aground in Prince William sound, Alaska. Pleas she made at the time for stiffer penalties for oil companies - to prevent anything similar ever happening again - seem to have had little effect. Then in 1991, as chief scientist at the US National Oceanic and Atmospheric Administration (NOAA), Earle led a study of the Persian Gulf after retreating Iraqi forces unleashed the largest marine oil spill in history.

The Deepwater Horizon spill strikes home particularly hard for Earle. As a 12-year-old, in 1947, she moved with her family to Florida's Gulf coast. Six years later she learned to dive off Clearwater, Florida - when, as she describes it, "the water was still clear". Earle went on to complete her master's and PhD based on the Gulf's fauna. In more than 50 years of diving, Earle has seen tremendous changes throughout the region, including the extinction of the Caribbean monk seal and a sharp drop in populations of large fish such as tuna, swordfish, marlin, grouper and snapper.

What worries her most about the current spill are the unknown effects of the dispersant chemicals used to break up oil into small droplets that sink into the water column. "If they put dispersants into any body of water without the presence of oil, people would be up in arms about the release of such toxic substances," she says. "But because they are being applied in the name of remediation, people stand by and say it's OK. But it isn't OK at all; it's making the Gulf a big experiment with no baseline to judge the real consequences."

Federal government biologists who approved the use of dispersants say the chemicals are the lesser of two evils: they are toxic to some extent, but they keep the oil from reaching sensitive wetland habitat along the coast. I ask Earle about this but, aside from the limited use of dispersants to protect specific marshes from approaching slicks, she will have none of it.

"Deploying dispersants at the well head and on the surface many miles from shore is shockingly irresponsible," she says. "It means you are taking oil that could be collected on the surface and [causing] it to go where it is impossible to recover. Life in the water column is exposed to the chemicals from the surface... and it's killing all the way."

Too much emphasis is being placed on the coasts where people live and not the open ocean where the marine life is, she says. Part of the problem is the "pathetic amount of investment" by government agencies in submersibles that would allow them to observe subsurface effects first-hand.