A Sea in Flames - Carl Safina [44]
But what are “plumes”? We don’t quite get from the scientists an indication of how dense they are. Are we talking murky clouds? Tiny amounts detectable only with instruments? Enough to kill plankton? Small fish? Even a 10-by-3-mile plume is only a fraction of the Gulf. Are there other, more widespread plumes?
Plume definition: something flowing within a different medium.
The farther from the source of the blowout, the less concentrated the oil and gas hydrocarbons in the plume. Currents determine where plumes go. Dispersants also break up oil. If oil gets broken into very small droplets, say 1 micron in size, it no longer floats but dissolves into the seawater. “Clean” seawater contains oil concentrations less than 1 part per billion; in every billion drops of seawater there’s less than one dissolved drop of oil. A polluted place, like a city harbor, may have between 100 and 800 drops of oil for every billion drops of seawater. You can also think of it as, say, 100 to 800 gallons of oil in every billion gallons of seawater. A billion gallons occupies about 5,000 cubic yards, or a space 100 yards long, 50 yards wide, and 1 yard deep. Two hundred gallons of oil would take up one cubic yard.
A bit of comparison. The Ixtoc blowout discharged a maximum of about 30,000 barrels per day. The present blowout is leaking perhaps twice that amount, so at any given distance from the blowout, our concentrations should be higher. Within a few hundred yards of the Ixtoc blowout, oil was 10,000 parts per billion. About 50 miles away, it was 5 parts per billion. Because the concentration gets lower and lower as oil travels away from the blowout, nobody knows much about how toxic the plumes of oil are.
They used to say “dilution is the solution to pollution,” and sometimes that’s right. If you think of a pollutant as anything that overwhelms the environment’s ability to harmlessly absorb it, dilution can work. (Animals’ bodies, though, often reconcentrate pollutants, much to their harm, so dilution isn’t always the solution.)
BP’s chief operating officer continues insisting that there exist no underwater oil plumes in “large concentrations.” He says that this may depend on “how you define what a plume is here.”
The way University of Georgia researcher Dr. Samantha Joye defines a plume, one large concentration of hydrocarbons from the blowout stretches at least 15 miles west of the gushing oil well, 3,600 feet beneath the sea surface, 3 miles wide, and up to 1,500 feet thick. The way University of South Florida researchers define a plume, there’s an even larger plume stretching more than 20 miles northeast of the oil well, with the hydrocarbons separated into one layer 1,200 feet below the surface and another 3,000 feet deep.
“The oil is on the surface,” says BP’s somnambulant CEO Tony Hayward. “There aren’t any plumes.” That’s certainly interesting, coming from someone whose company is blasting dispersants into the oil right at the seafloor as it emerges from the broken pipe, to keep the oil below the surface, and sending planes to carpet-bomb the slicks with more dispersant to sink the oil that has risen.
So how do you define plumes? In some places there’s enough oil to discolor the water. But in most places, water samples come up clear. Yet the dissolved hydrocarbons show up vividly on instruments, and in some samples you can smell them. That’s plumes.
Plumes are more evidence that there’s more oil leaking than we’re seeing. Because the Purdue University estimate and these reports of massive plumes seem so at odds with BP’s continual 5,000-barrel-a-day drumroll, scientists want to send sophisticated instruments to the ocean floor to get a far more accurate picture of how much oil is really gushing from the well.
“The answer is no to that,” a BP spokesman says. “We’re not going to take any extra efforts now to calculate flow there.”
That’s just outrageous. Now I’m really angry. How does BP get to decide