Gulf Oil Spill Disappearance: Microbes Eat Up the Oil

  • News
  • Thread starter Evo
  • Start date
  • Tags
    Oil
In summary, the vast majority of the oil spilled in the Gulf of Mexico has disappeared, and the cleanup crew is relying on microbes to do the job.
  • #1
Evo
Staff Emeritus
Science Advisor
24,017
3,337
Where's the oil?

Reminds me of the huge Ixtaca oil spill that also disappeared.

Mighty oil-eating microbes help clean up the Gulf

Where is all the oil? Nearly two weeks after BP finally capped the biggest oil spill in U.S. history, the oil slicks that once spread across thousands of miles of the Gulf of Mexico have largely disappeared. Nor has much oil washed up on the sandy beaches and marshes along the Louisiana coast. And the small cleanup army in the Gulf has only managed to skim up a tiny fraction of the millions of gallons of oil spilled in the 100 days since the Deepwater Horizon rig went up in flames.

So where did the oil go? "Some of the oil evaporates," explains Edward Bouwer, professor of environmental engineering at Johns Hopkins University. That’s especially true for the more toxic components of oil, which tend to be very volatile, he says. Jeffrey W. Short, a scientist with the environmental group Oceana, told the New York Times that as much as 40 percent of the oil might have evaporated when it reached the surface.



Perhaps the most important cause of the oil’s disappearance, some researchers suspect, is that the oil has been devoured by microbes. The lesson from past spills is that the lion’s share of the cleanup work is done by nature in the form of oil-eating bacteria and fungi. The microbes break down the hydrocarbons in oil to use as fuel to grow and reproduce. A bit of oil in the water is like a feeding frenzy, causing microbial populations to grow exponentially.

Typically, there are enough microbes in the ocean to consume half of any oil spilled in a month or two, says Howarth. Such microbes have been found in every ocean of the world sampled, from the Arctic to Antarctica. But there are reasons to think that the process may occur more quickly in the Gulf than in other oceans.

http://news.yahoo.com/s/ynews_excl/ynews_excl_sc3270 [Broken]
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
This makes me feel good :)
 
  • #3
microbes will do a better job then the cleanup crew.
friend from college did his thesis on oil eating microbes, he was doing soil samples at oil contaminated land and found the same activity going on a few meters down.
 
  • #4
Good job nature.
 
  • #5
Out of sight does not necessarily mean out of mind. The use of dispersants to break the oil up into smaller pieces and the fact that this spill has been associated with large underwater oil plumes means that simply looking at the amount of oil on the surface of the water will not give a good picture of how much oil is left. However, the Yahoo piece is right that microbes are doing a lot of the cleanup work. Clearly the gulf's microbial ecosystem has a massive capacity to consume hydrocarbons. For example, the gulf has a naturally leaky seafloor that leaks around 1,500 to 4,000 bbl per day (the gulf spill, however, was estimated at 35,000 to 60,000 bbl per day). However, not all types of oil can be digested by the bacteria:
One specialist genus, Alcanivorax, appears on the scene first: It goes from being nearly undetectable in the absence of oil to overtaking all other microbes in oil-treated environments. Alcanivorax metabolizes branched-chain alkanes, which are oil's lightest fractions. As the alkanes disappear, Alcanivorax's numbers drop and then other bacteria take over to finish off what's left. One late-arriving genus, Cyclosticus, consumes aromatic hydrocarbons, the next heaviest oil fraction after alkanes. But no microbe genus can digest oil's heaviest fraction, the asphaltenes.
Source: http://pubs.acs.org/cen/news/88/i31/8831news1.html [Broken]

Furthermore, the Yahoo estimates seem optimistic given the figures quoted in the C&EN piece:
With these favorable conditions, aerobic bacteria could clear Gulf waters of the oil spill in a couple of years, [University of North Carolina, Chapel Hill Professor Andreas Teske] predicts. The use of chemical dispersants—which break the oil up into micrometer-sized droplets—is accelerating that process, he says, because surface-area–to-volume ratios increase with decreasing particle size.

Although microbes may degrade the oil quickly, [University of California, Santa Barbara Professor David Valentine] points out that they could eventually pose risks to the Gulf's ecosystem, particularly in the deep ocean. The introduction of a new food source, oil hydrocarbons, to the deep gulf could generate bacterial blooms that eventually become vast quantities of biomass. Other bacteria would then metabolize this biomass and deplete oxygen to levels low enough to be dangerous for other organisms, Valentine says.

Finally, on oil washing up onshore, the piece notes that:
Huettel and Kostka, who collaborate on coastal studies of microbial oil degredation, have recently found tar balls in sediments 50 centimeters deep in Florida beach sands. "It would take a hurricane to remove them," Huettel says. Scientists worry most that buried oil will secrete toxins for decades. Researchers have observed a similar time course in Prince Williams Sound, Alaska—the scene of the 1989 Exxon Valdez spill—and other coastal areas hit by major spills.

There is certainly cause to celebrate that oil is no longer spilling into the gulf and that the gulf's microbes seem to be doing a good job cleaning up the spill, but the effect of the spill on the gulf ecosystem are not likely going to be over anytime soon.
 
Last edited by a moderator:
  • #6
Ygggdrasil said:
Out of sight does not necessarily mean out of mind. The use of dispersants to break the oil up into smaller pieces and the fact that this spill has been associated with large underwater oil plumes means that simply looking at the amount of oil on the surface of the water will not give a good picture of how much oil is left. However, the Yahoo piece is right that microbes are doing a lot of the cleanup work. Clearly the gulf's microbial ecosystem has a massive capacity to consume hydrocarbons. For example, the gulf has a naturally leaky seafloor that leaks around 1,500 to 4,000 bbl per day (the gulf spill, however, was estimated at 35,000 to 60,000 bbl per day). However, not all types of oil can be digested by the bacteria:
Source: http://pubs.acs.org/cen/news/88/i31/8831news1.html [Broken]

Furthermore, the Yahoo estimates seem optimistic given the figures quoted in the C&EN piece:
From your C&EN piece
Whatever genera are present, says Joseph Suflita, a microbiologist at Oklahoma University, Norman, "the most important thing is that oil-degrading bacteria have the oxygen and nutrients they need to do the job." Oxygen is crucial because without it, anaerobic species, which use sulfate in place of oxygen during respiration, replace aerobic bacteria. These sulfate-dependent bacteria provide a slower path to oil degradation than aerobic microbes, Florida State's Kostka says. In laboratory tests performed by his graduate students, aerobic bacteria cultured from spill-impacted beaches along the Gulf coast cleared oil from water solutions in a day, while anaerobes took weeks to achieve the same effect. But UC Santa Barbara's Valentine says that the oxygen reductions he has observed aren't great enough to block the activity of aerobic microbes.

Your source spoke of the Exxon Valdez
Scientists worry most that buried oil will secrete toxins for decades. Researchers have observed a similar time course in Prince Williams Sound, Alaska—the scene of the 1989 Exxon Valdez spill—and other coastal areas hit by major spills.
But the gulf oil spill is nothing like that spill.
Microbes grow faster in the warmer water of the Gulf than they do in, say, the cool waters off Alaska, where the Exxon Valdez spill occurred. Moreover, the Gulf is hardly pristine. Even before humans started drilling for oil in the Gulf — and spilling lots of it — oil naturally seeped into the water. As a result, the Gulf evolved a rich collection of petroleum-loving microbes, ready to pounce on any new spill. The microbes are clever and tough, observes Samantha Joye, microbial geochemist at the University of Georgia. Joye has shown that oxygen levels in parts of the Gulf contaminated with oil have dropped. Since microbes need oxygen to eat the petroleum, that’s evidence that the microbes are hard at work.

The controversial dispersant used to break up the oil as it gushed from the deep-sea well may have helped the microbes do their work. Microbes can more easily consume small drops of oil than big ones. And there is evidence the microbes like to munch on the dispersant as well.
 
Last edited by a moderator:
  • #7
The oil is below the surface. There is no mystery.

Anyone with an elementary knowledge of this knows about the bacteria. In fact, one of the big concerns is that the oil-eating bacteria will cause dead zones due to depleted oxygen.

The only reason the oil didn't hit land in greater quantities was that the winds were favorable. They kept shifting, which helped to keep the oil out at sea. But we know nothing about how ecosystems have been or will be affected.

In short, there is no news here. It may take years or more before we fully understand the impact of this event. But there is no doubt that nature has conspired in our favor. Thanks to the efforts of the Obama admin - Steven Chu in particular - and the lack of hurricanes so far [only a couple of near misses] the damage from this might still be minimized. Note that the leak was contained almost six weeks sooner than estimated! Great job Chu! Congratulations to Obama, all of his advisors, Thad Allen, and all who helped to contain this disaster.

With any luck, no significant amount of oil went deep into the critical breeding grounds of La. wetlands, but we don't know that yet.
 
Last edited:
  • #8
Was the oil in the Exxon Valdez in some stage of refinment or was it straight from a well head ?
 
  • #9
RonL said:
Was the oil in the Exxon Valdez in some stage of refinment or was it straight from a well head ?

The oil in the Valdez disaster was heavy, sour crude.

Over twenty years later, it can still be found just under the rocks, on local beaches. Once you get below the surface, there isn't enough oxygen for the bacteria to feast, so the oil remains.

The herring population never did return.
 
  • #10
Regarding the data quoted from Joel Kostka's lab, I don't think that test was meant to be representative of the time it would take the microbes to clear the levels of oil in the gulf, but merely as an example to compare the rates of action of the two type of bacteria.

Regarding the buried oil in sand, the C&EN piece writes:
Oxygen levels plummet to near zero in sand deeper than 10 or 15 cm, while muddier sediments become hypoxic below just 2 or 3 cm, Florida State's Huettel says. And oil that washes ashore is typically weathered into tar-balls, which have very low surface-area to volume ratios. These conditions are a double whammy: Slow, anaerobic bacteria must confront a dense, coagulated product, with very stable aromatic carbon bonds that resist digestion.

Which are valid reasons to worry that the digestion of these oil deposits will not occur quickly even with the increased temperatures at the gulf.
 
  • #11
Evo said:
From your C&EN piece

Your source spoke of the Exxon Valdez But the gulf oil spill is nothing like that spill.
Yes I believe I read that it was expected that the elevated temperatures in the Gulf (vs Valdez) would cause the DeepWater oil to breakdown 5-10X faster?
 
  • #12
Something of interest on ABC evening news yesterday, the birds that were cleaned were about 2,800 and nearly 1/2 died, the birds from the Valdez were near 250,000. I remember the concerne about birds along the coast, I think the numbers being low would be related to how warm water and air would cause vapors to rise and smells would cause most to move away and stay more inland.

Only time will tell but it seems there have been a lot of unexpected things here.
 
  • #13
Ivan Seeking said:
Thanks to the efforts of the Obama admin - Steven Chu in particular - and the lack of hurricanes so far [only a couple of near misses] the damage from this might still be minimized. Note that the leak was contained almost six weeks sooner than estimated! Great job Chu! Congratulations to Obama, all of his advisors, Thad Allen, and all who helped to contain this disaster.
Perhaps my sarcasm detector is malfunctioning, but I'm not detecting any here. So are you really seriously claiming that those people are directly responsible for the flow of oil being stopped 6 weeks sooner than once estimated? Based on what?! :eek:
 
  • #14
russ_watters said:
Perhaps my sarcasm detector is malfunctioning, but I'm not detecting any here. So are you really seriously claiming that those people are directly responsible for the flow of oil being stopped 6 weeks sooner than once estimated? Based on what?! :eek:
I thought Ivan was concerned about the flow taking months longer than expected to get stopped? Before his last post, of course. And thanks should go to nature for the cleanup. The Earth has an amazing way of healing itself.
 
  • #15
russ_watters said:
Perhaps my sarcasm detector is malfunctioning, but I'm not detecting any here. So are you really seriously claiming that those people are directly responsible for the flow of oil being stopped 6 weeks sooner than once estimated? Based on what?! :eek:
:biggrin: Been waiting for this post! :biggrin:
 
  • #16
Gokul43201 said:
:biggrin: Been waiting for this post! :biggrin:
I love how it has to be me - the post was from yesterday and a bunch of people let it go!
 
  • #17
i feel like i should do my part here, and maybe contribute a little extra biological waste products this weekend to go drifting down the Cahaba, and eventually into the Gulf.
 
  • #18
The oil at the surface disappears, but far below the surface the oil will not disappear so quickly. Oil out of sight does not mean it does no harm.
 
  • #19
heusdens said:
The oil at the surface disappears, but far below the surface the oil will not disappear so quickly. Oil out of sight does not mean it does no harm.
I've never been convinced that something can 'disappear'.
 
  • #20
Alfi said:
I've never been convinced that something can 'disappear'.
As the law of conservation of mass implies, nothing really "disappears" but it can be eaten, evaporated, burned or diluted (or, of course, skimmed).
 
  • #21
russ_watters said:
As the law of conservation of mass implies, nothing really "disappears" but it can be eaten...

It appears much of the oil is simply being eaten. More than a month since your post, Russ, the good news continues: http://news.yahoo.com/s/ap/20100907/ap_on_sc/us_sci_gulf_spill_where_s_the_oil" [Broken]

The title is somewhat misleading, as O2 in the oil-laden areas is indeed down by about 20%, but that's not enough to create the dreaded "dead zones." For that to have happened, O2 levels would have had to drop another 70%.

On another thread someone mentioned decades of Mississippi River pollution in the Gulf as part of the reason why has "recovered" so quickly, that it's already partially adapted to these conditions. Evolution in action? Yes, but that evolution began a century before the spill, probably earlier than that, during the days when steamboats and tug-driven barges plied their way up and down the river and the supported industries dumped untreated sewage and industrial waste into the river.

Of course this makes me wonder what the Gulf looked like 200 years ago. Or 500. Was it a pristine, clear-water environment, or has organic Mississippi detritus always muddied its waters? (alluvium settles rather quickly, depositing itself in the Delta)
 
Last edited by a moderator:
  • #22
mugaliens said:
...
On another thread someone mentioned decades of Mississippi River pollution in the Gulf as part of the reason why has "recovered" so quickly, that it's already partially adapted to these conditions. Evolution in action? Yes, but that evolution began a century before the spill, probably earlier than that, during the days when steamboats and tug-driven barges plied their way up and down the river and the supported industries dumped untreated sewage and industrial waste into the river.

Of course this makes me wonder what the Gulf looked like 200 years ago. Or 500. Was it a pristine, clear-water environment, or has organic Mississippi detritus always muddied its waters? (alluvium settles rather quickly, depositing itself in the Delta)
Sewage does not equal oil, and prior man made oil leakage coming down the Mississippi is trivial compared to natural leakage from the sea floor, about an Exxon Valdez per year world wide.
https://www.physicsforums.com/showpost.php?p=2724440&postcount=457
 
  • #23
I'm just glad no one is thanking Obama for this one. If it rained during a drought, some idiot would thank Obama. If a plane crashed killing 180 with the sole survivor being a puppy, some idiot would thank Obama.

This is a classic case of villainizing oil. And really for no good reason. It's getting to the point where people mindlessly recite chants about how bad oil is, or hydrocarbons, or global warming. We're being trained to lose our minds.
 
Last edited:
  • #25
Hmm... I can understand thanking Thad Allen (that guy is pretty slick, hard not to like him... all business), and maybe Chu to a lesser extent. But why thank Obama? All he did was obfuscate the situation, invest government time and effort in a private company's problem, and mix up messages. Hardly seems like "mission accomplished" for him.
 
  • #26
mheslep said:
Sewage does not equal oil, and prior man made oil leakage coming down the Mississippi is trivial compared to natural leakage from the sea floor, about an Exxon Valdez per year world wide.
https://www.physicsforums.com/showpost.php?p=2724440&postcount=457

Ok, folks, let's back off the Obama stuff. I'm not a fan, but I'm not going to bash him, either.

mheslep: It matters somewhat, but not too much, what one throws into the environment. Beginning with the smallest, most rapidly reproducing forms of life, they adapt. Oil has been leaking into the environment for millions of years. It might not be tasty to your or I, but life adapted. Given the vast amounts of oil in the Gulf, is it any wonder, really, that the Gulf is populated with microbes which love oil?

For that matter, we've been leaking oil and thousands of other chemicals down the Mississippi for hundreds of years. Is it any wonder that over thousands of lifecycles some of those critters developed a taste for some of what we've been dumping? Good grief - we found microbes living off the radiation itself at 3 mile island - where did they come from?

You wrote: "man made oil leakage coming down the Mississippi is trivial compared to natural leakage from the sea floor, about an Exxon Valdez per year world wide."

Yep. I do sincerely hope no one uses this fact to discount the spill or our responsibility to ensure things like this don't happen in the future. But it is a good way to put things into perspective. An oil spill, even a major one, does not forever ruin our planet. Even so, there are other ways we are ruining our planet, including vast overfishing, massive pollution which our oceans cannot absorb and which are causing the die-off of ocean reefs en-masse.
 
  • #27
Would anyone disagree that we can learn a valuable lesson from this? That lesson being: humankind's impact on the environment is often over stated and sometimes wildly exaggerated. While it is never advisable to intentionally disregard our environment's safety and well-being, we should feel more comfortable growing as a species within it and listen less to the stereotypical "tree-hugger."
 
  • #28
I find it ridiculous that we draw any conclusions about damage, or successful metabolism this early in the game. Like it or not, this is going to take a few years for the damage to become apparent if the oil has massively entered the food chain in the gulf, or for the creation of hypoxic zones as a result of the Oxygen needed for microbes to "eat" the oil. Personally, I expect that there will be some serious damage, but this on generational (for sea-life) time-scales and it has to move into our neck of the food-chain-woods for us to notice.

If there's no negative impact apparent after 5 years, I'll start to get optimistic. If there's damage that is transient, I'll be optimistic, but right now given the massive use of dispersants and the depth at which plumes were found... it would be foolish to draw positive conclusions, and too early to expect disaster.

If you're ready to take away a lesson already, you've essentially walked out of a lecture after 5 minutes of the introduction, assuming that you grasp the whole.
 
  • #29
nismaratwork said:
If you're ready to take away a lesson already, you've essentially walked out of a lecture after 5 minutes of the introduction, assuming that you grasp the whole.

I would argue it's more like walking out of a lecture after 5 minutes of the introduction because you realize you've already heard that lecture 40 times. Ixtoc, Castillo De Belver, Greenpoint (to a lesser degree).
 
  • #30
FlexGunship said:
I would argue it's more like walking out of a lecture after 5 minutes of the introduction because you realize you've already heard that lecture 40 times. Ixtoc, Castillo De Belver, Greenpoint (to a lesser degree).

Well, time will tell right? It's not as though worrying can be beneficial right now, and there's nothing practical to be done either. Wait and see, maybe hope a bit, but beyond that... *shrug*.

It's not even worth arguing about at this point in my view.
 
  • #31
nismaratwork said:
Well, time will tell right? It's not as though worrying can be beneficial right now, and there's nothing practical to be done either. Wait and see, maybe hope a bit, but beyond that... *shrug*.

It's not even worth arguing about at this point in my view.

A sensible stance. I'll agree with that. If it turns out that we've really botched the environment up this time, it would be important to know either way. Hopefully it doesn't become an excuse for oil companies to become more careless with their drilling practices.
 
  • #32
FlexGunship said:
Hopefully it doesn't become an excuse for oil companies to become more careless with their drilling practices.

That's definitely a valid concern! Given the economic impact to BP thus far, however, I think that's probably a much stronger incentive for oil companies to avoid mishaps than would be any change to the regulations.
 
  • #34
mugaliens said:
That's definitely a valid concern! Given the economic impact to BP thus far, however, I think that's probably a much stronger incentive for oil companies to avoid mishaps than would be any change to the regulations.

Indeed, and when you add public outrage and increased sensitivity (for a time at least), plus the fallout that's coming when the families of dead and injured oil-platform workers sue... it's not a net incentive. I think oil companies are lying, cheating, amoral scum, but even I doubt that any want to see a repeat of this or anything like it. To see such an event occur anytime soon would shake public confidence in much the way that rapid-fire airline crashes would. Just try to explain on the news about the true nature of random occurrences over the screaming of shock-jocks and frightened people.
 
  • #35
edward said:
There appears to be a lot of oil in a sludge/scum form on the bottom of the gulf.

http://abcnews.go.com/WN/oil-bp-spill-found-bottom-gulf/story?id=11618039

Damn, just when I thought we had dodged the bullet.

Edit: On second thought that may be the best place for it.

Oh my goodness! Scientists trying to put the kabosh on the truth?

Gee, where in the world have I seen that happen before? (reference to another forum and a certain mod who abused his authority to push his non-truthful agenda).

Go Professor Joye!
 
<h2>1. What are microbes and how do they eat up oil?</h2><p>Microbes are microscopic organisms that can break down and consume organic materials, such as oil. They have enzymes that help them break down the complex molecules in oil into smaller, more manageable components that they can use as food.</p><h2>2. How did microbes help clean up the Gulf oil spill?</h2><p>After the Deepwater Horizon oil spill in 2010, scientists discovered that certain types of microbes were able to consume the oil that had leaked into the Gulf of Mexico. These microbes multiplied rapidly and were able to break down a significant amount of the oil, helping to reduce the size and impact of the spill.</p><h2>3. Are there any potential negative effects of using microbes to clean up oil spills?</h2><p>While microbes can be effective in cleaning up oil spills, there are some potential negative effects to consider. If the population of microbes grows too large, they can deplete the oxygen in the water, leading to dead zones where other marine life cannot survive. Additionally, some microbes may produce toxins as a byproduct of consuming oil, which could harm other organisms in the ecosystem.</p><h2>4. How long does it take for microbes to clean up an oil spill?</h2><p>The time it takes for microbes to clean up an oil spill depends on various factors, such as the amount of oil spilled, the type of oil, and environmental conditions. In the case of the Gulf oil spill, it took several months for microbes to significantly reduce the amount of oil in the water.</p><h2>5. Can microbes be used to clean up all types of oil spills?</h2><p>Microbes can be effective in cleaning up many types of oil spills, but they may not be suitable for all situations. For example, in colder environments, the metabolism of microbes may slow down, making them less effective at breaking down oil. Additionally, some types of oil may be more difficult for microbes to consume, so other methods may be needed for cleanup.</p>

1. What are microbes and how do they eat up oil?

Microbes are microscopic organisms that can break down and consume organic materials, such as oil. They have enzymes that help them break down the complex molecules in oil into smaller, more manageable components that they can use as food.

2. How did microbes help clean up the Gulf oil spill?

After the Deepwater Horizon oil spill in 2010, scientists discovered that certain types of microbes were able to consume the oil that had leaked into the Gulf of Mexico. These microbes multiplied rapidly and were able to break down a significant amount of the oil, helping to reduce the size and impact of the spill.

3. Are there any potential negative effects of using microbes to clean up oil spills?

While microbes can be effective in cleaning up oil spills, there are some potential negative effects to consider. If the population of microbes grows too large, they can deplete the oxygen in the water, leading to dead zones where other marine life cannot survive. Additionally, some microbes may produce toxins as a byproduct of consuming oil, which could harm other organisms in the ecosystem.

4. How long does it take for microbes to clean up an oil spill?

The time it takes for microbes to clean up an oil spill depends on various factors, such as the amount of oil spilled, the type of oil, and environmental conditions. In the case of the Gulf oil spill, it took several months for microbes to significantly reduce the amount of oil in the water.

5. Can microbes be used to clean up all types of oil spills?

Microbes can be effective in cleaning up many types of oil spills, but they may not be suitable for all situations. For example, in colder environments, the metabolism of microbes may slow down, making them less effective at breaking down oil. Additionally, some types of oil may be more difficult for microbes to consume, so other methods may be needed for cleanup.

Similar threads

Replies
12
Views
8K
Back
Top