Posted on 04/29/2015 10:54:20 AM PDT by thackney
Like cars, some microbes use oil as fuel. Such microorganisms are a big reason why BP's 2010 oil spill in the Gulf of Mexico was not far worse.
"The microbes did a spectacular job of eating a lot of the natural gas," says biogeochemist Chris Reddy of the Woods Hole Oceanographic Institution. The relatively small hydrocarbon molecules in natural gas are the easiest for microorganisms to eat. "The rate and capacity is a mind-boggling testament to microbes," he adds.
As Reddy suggests, the microbes got help from the nature of the oil spilled—so-called Louisiana light, sweet crude mixed with natural gas, as opposed to bitumen or other heavy, gunky oils. "It's a whole lot easier to degrade," says Christopher D'Elia, a biologist at Louisiana State University and dean of the School of the Coast and Environment. "The bacteria had something that was more tractable."
More than 150 different molecules make up the toxic stew of hydrocarbons that spewed from BP's Macondo well on the Gulf of Mexico seafloor. The microbes chewed through the smaller, dispersed hydrocarbons (and the dispersants themselves) relatively quickly, helped by the fact that these molecules can dissolve in water. "I give them a 7 out of 10," says biogeochemist David Valentine of the University of California, Santa Barbara, of the microbes’ performance eating the oil spill.
Ocean currents, in addition to keeping the spilled oil offshore, spurred microbial activity amidst the oil spill. That continuous mixing of the water allowed a bacterial bloom to turn millions of barrels of oil into an estimated 100 sextillion microbial cells of ethane-consuming Colwellia, aromatic-eating Cycloclasticus, alkane-eating Oceanospirillales, oil-eating Alcanovorax, methane-loving Methylococcaceae and other species, including at least one previously unknown to science.
But even the ravenous microbes could not clean it all—and much of what they consumed (natural gas components like methane, ethane, butane, propane and pentane) does not legally count as part of the oil spill. Plus, plenty of tarlike hydrocarbons—which are far too big for microbes to chew up—spilled, too. Reddy and his colleagues still head down to the Gulf of Mexico as often as possible to walk the beaches and collect samples. "We're trying to see who's the toughest kid on the block," he says of the spill’s components, in an attempt to figure out why these hydrocarbons cannot be biodegraded or even broken down by sunlight. In fact, sunlight alone can transform the oil that made it to the surface uneaten. "Nature has a vast toolbox to combat oil," he adds, although it remains unclear whether sunlight-transformed hydrocarbons are worse or better from a toxicology perspective.
The bacterial blooms also seem to be at least partially responsible for the oily marine snow that coated the bottom of the Gulf of Mexico in the wake of the Macondo blowout—again, an unexpected after-effect with unknown impacts. "The stuff is almost everywhere you look," says biogeochemist Samantha Joye of The University of Georgia, describing her surveys of the sediments under 1,000 meters or more of water with submersible Alvin, among other tools. "Up to 15 percent of what was discharged is on the seabed. That's a pretty remarkable number, given that it wasn't initially thought of as a potential fate for oil."
Even the smaller molecules cannot be consumed if there are not enough nutrients in the water as well, like nitrogen or phosphorus. "Nutrients regulated biodegradation," Joye says. "That could be why so much oil sedimented out, they degraded as much as they could." In fact, the microbes may have been hampered not only by limited nutrients because the microbial population boom may have meant an accompanying boom in their predators or in the various viruses that can infect these spill-eaters. Moreover, one of the biggest requirements for these microbes to eat hydrocarbons—oxygen—is not present at all in the sediments of the deep or the muck of Louisiana marshes. That is why oil from the Macondo well persists in those places five years later—and perhaps for eons to come.
"Microbes are like teenagers," Reddy says. "You can ask them to clean the garage over the weekend. Can they do it? Yes. Will they do it? Maybe. Will they do as good a job as you want? Probably not."
Nature healed what man inflicted in 1979 Gulf spill Read more: June 10, 2010" "A lot of the fishermen around here will tell you that the fish never came back,'' says Vega Morales. ``They'll say, `Oh, in the old days, you could catch fish with your hat, it was so easy.' That's how we are, always talking about the one that got away. But the truth is, after maybe nine months or so, it was back to normal." " (Ixtoc 1)
"Soto, who followed the fish and shrimp population off Mexico closely, found to his surprise that for most species the numbers had returned to normal within two years."
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Oil Cleanup Expert Comments on Gulf Spill
"Every year 2 million to 12 million tons of oil naturally seep from the ocean floor and into the sea. In fact, many of the deposits in the Gulf of Mexico were discovered by observing these oil seeps, which is why the hydrocarbon degraders are everywhere, waiting for their “dinner” or fuel. Fishermen should be prepared for the extra catches that are coming because after every major oil spill there’s an explosion of local fish."
"But before a fish explosion can happen, the microorganisms need to be able to get to the oil and digest it. Since oil and water don’t mix, adding a dispersant will accelerate the breakdown of the oil, making it more available to the microorganisms."
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1979's Ixtoc oil well blowout in Gulf of Mexico has startling parallels to current disaster
"Even with those obstacles, fishers still managed to amass an impressive catch in 1979 -- when oil was gushing into the Gulf."
"Researchers in Campeche found shrimping that year enjoyed a high. The total tonnage of seafood caught in the Gulf of Mexico grew by 5.9 percent compared with the previous 12 months, and octopus capture in the Bay of Campeche beat the previous record by 50 percent."
"Tunnell's follow-up research into life near Texas beaches showed that organisms whose populations were apparently reduced by the massive spill replenished themselves within a few years."
This ‘spill’ was oil in it’s natural state... the kind of stuff that’s been seeping into oceans since the beginning of time.
The problem with the EXXON spill was it was ‘cracked’ oil - something the oceans’ didn’t know how to deal with.
What?
From wikipedia:
Because Prince William Sound contained many rocky coves where the oil collected, the decision was made to displace it with high-pressure hot water. However, this also displaced and destroyed the microbial populations on the shoreline; many of these organisms (e.g. plankton) are the basis of the coastal marine food chain, and others (e.g. certain bacteria and fungi) are capable of facilitating the biodegradation of oil. At the time, both scientific advice and public pressure was to clean everything, but since then, a much greater understanding of natural and facilitated remediation processes has developed, due somewhat in part to the opportunity presented for study by the Exxon Valdez spill.
:) Thanks.
Degradation still happens. Different microbes for different environments, even underground. The oil itself becomes a set of nutrients.
Right you are. The bigger problem with really old gas stations is contamination of the soil by the lead "octane boosters" that used to be added to gasolines (tetramethyl to tetraethyl lead). Even if the bugs eat the hydrocarbon parts, the lead heavy metal remains.
My dad often says that the U.S. military needs to develop a new biological weapon to deploy in the middle east that turns crude oil into sand.
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