Are Dispersants Killing Natural Oil Eaters?

Photo courtesy NASA

Facts matter: Sign up for the free Mother Jones Daily newsletter. Support our nonprofit reporting. Subscribe to our print magazine.


BP has dumped about 10,000 gallons of dispersants onto and under Gulf waters in the past month. The idea being that the dispersants will break the oil down into small enough globs for natural marine microbes to clean up.

We know these dispersants are toxic. In lab tests, Corexit—BP’s favorite—kills shrimp and fish. Now David Valentine, a biogeochemist at the University of California Santa Barbara, warns the stuff may be riskier than just its toxicity. Corexit may undermine the microbes that naturally eat oil.

Some of the most potent oil-eaters—Alcanivorax borkumensis—are relatively rare organisms that have evolved to eat hydrocarbons from naturally occurring oil seeps. Valentine tells Eli Kintisch at Science Insider that after spills, Alcanivorax tend to be the dominant microbes found near the oil and that they secrete their own surfactant molecules to break up the oil before consuming the hydrocarbons. Other microbes don’t make surfactants but devour oil already broken into small enough globs—including those broken down by Alcanivorax.

What we don’t know is how the surfactants in Corexit and its ilk might affect the ability of Alcanivorax and other surfactant-makers to eat oil. Could Corexit exclude Alcanivorax from binding to the oil? Could it affect the way microbes makes their own surfactants? Could Corexit render natural surfactants less effective?

The National Science Foundation has awarded Valentine a grant to study the problem.

BTW, experiments from the 1980s done on wildlife in the wild (nesting Leach’s Storm-Petrels on Grand Island off  Newfoundland) found that birds exposed to crude oil or to Corexit lost more eggs and chicks than did control birds. Of the adult birds that survived contamination with higher levels of oil or Corexit, many fewer returned to breed the following year than did control birds—intimating their exposure was lethal in the long run if not the short run.

(If you appreciate our BP coverage, please consider making a tax-deductible donation.)

THE TRUTH...

is the first thing despots go after. An unwavering commitment to it is probably what draws you to Mother Jones' journalism. And as we're seeing in the US and the world around, authoritarians seek to poison the discourse and the way we relate to each other because they can't stand people coming together around a shared sense of the truth—it's a huge threat to them.

Which is also a pretty great way to describe Mother Jones' mission: People coming together around the truth to hold power accountable.

And right now, we need to raise about $400,000 from our online readers over the next two months to hit our annual goal and make good on that mission. Read more about the information war we find ourselves in and how people-powered, independent reporting can and must rise to the challenge—and please support our team's truth-telling journalism with a donation if you can right now.

payment methods

THE TRUTH...

is the first thing despots go after. An unwavering commitment to it is probably what draws you to Mother Jones' journalism. And as we're seeing in the US and the world around, authoritarians seek to poison the discourse and the way we relate to each other because they can't stand people coming together around a shared sense of the truth—it's a huge threat to them.

Which is also a pretty great way to describe Mother Jones' mission: People coming together around the truth to hold power accountable.

And right now, we need to raise about $400,000 from our online readers over the next two months to hit our annual goal and make good on that mission. Read more about the information war we find ourselves in and how people-powered, independent reporting can and must rise to the challenge—and please support our team's truth-telling journalism with a donation if you can right now.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate