By Janet Raloff
The catastrophic explosion on April 20 of an offshore oil-exploration platform in the Gulf of Mexico sent oil slicks coasting toward shorelines from Louisiana to Florida. Now research vessels are tracking a more stealthy threat: huge clouds of diffuse, nearly invisible oil droplets hovering deep below the surface.
New data indicate these invisible plumes form shifting strata that fan out in a host of directions from the gushing wellhead, more than 1.5 kilometers below the water’s surface. These clouds could substantially increase estimates of the total amount of oil spilled and could poison deep-dwelling critters that provide the base of the marine food web.
BP North America — the well’s owner — had claimed for weeks that daily spill rates likely peaked at about 5,000 barrels, or 210,000 gallons. But a new oil-collection system that the company set up on June 3 was hauling in just shy of 15,000 barrels of crude per day by June 8.