sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery

 

Sail-World.com : WHOI Study - Microbes consumed oil in Gulf slick at unexpected rates

WHOI Study - Microbes consumed oil in Gulf slick at unexpected rates

'From the deck of the research vessel Endeavor, Ben Van Mooy (right) and others survey the scene near the burning Deepwater Horizon oil rig in the Gulf of Mexico in June, 2010. Van Mooy was a member of a team of WHOI scientists who went to the Gulf to study aspects of the oil spill, including how fast it was flowing out of the ruptured wellhead and whether it was flowing in a deep plume of hydrocarbons. Van Mooy’s experiments focused on whether microbes were eating oil in the surface slick and in'    Woods Hole Oceanographic Institution (WHOI) ©

More than a year after the largest oil spill in history, perhaps the dominant lingering question about the Deepwater Horizon spill is, 'What happened to the oil?' Now, in the first published study to explain the role of microbes in breaking down the oil slick on the surface of the Gulf of Mexico, Woods Hole Oceanographic Institution (WHOI) researchers have come up with answers that represent both surprisingly good news and a head-scratching mystery.

In research scheduled to be published in the Aug. 2 online edition of Environmental Research Letters, the WHOI team studied samples from the surface oil slick and surrounding Gulf waters. They found that bacterial microbes inside the slick degraded the oil at a rate five times faster than microbes outside the slick—accounting in large part for the disappearance of the slick some three weeks after Deepwater Horizon’s Macondo well was shut off.

At the same time, the researchers observed no increase in the number of microbes inside the slick—something that would be expected as a byproduct of increased consumption, or respiration, of the oil. In this process, respiration combines food (oil in this case) and oxygen to create carbon dioxide and energy.

'What did they do with the energy they gained from this increased respiration?' asked WHOI chemist Benjamin Van Mooy, senior author of the study. 'They didn’t use it to multiply. It’s a real mystery,' he said.

Van Mooy and his team were nearly equally taken aback by the ability of the microbes to chow down on the oil in the first place. Going into the study, he said, 'We thought microbe respiration was going to be minimal.' This was because nutrients such as nitrogen and phosphorus—usually essential to enable microbes to grow and make new cells—were scarce in the water and oil in the slick. 'We thought the microbes would not be able to respond,' Van Mooy said.

But the WHOI researchers found, to the contrary, that the bacteria not only responded, but did so at a very high rate. They discovered this by using a special sensor called an oxygen optode to track the changing oxygen levels in water samples taken from the slick. If the microbes were respiring slowly, then oxygen levels would decrease slowly; if they respired quickly, the oxygen would decrease quickly.

'We found that the answer was ‘quick,’' Van Mooy said. 'By a lot.'

Bethanie Edwards, a biochemist in Van Mooy’s lab and lead author of the paper, said she too was 'very surprised' by the amount of oil consumption by the microbes. 'It’s not what we expected to see.' She added that she was also 'a little afraid' that oil companies and others might use the results to try to convince the public that spills can do relatively little harm. 'They could say, ‘Look, we can put oil into the environment and the microbes will eat it,’' she said.

A new technique for determing the concentration of oxygen in a liquid sample uses a laser (coming from the green fiber, right) and an oxygen-sensitive sticker called an optode (pale spot) inside the sample bottle. When struck by the laser, the sticker fluoresces; the wavelength of the light it gives off indicates the concentration of oxygen in the fluid around it. WHOI chemist Ben Van Mooy used this method to monitor microbial activity in samples of water taken from within and outside the oil sl -  Woods Hole Oceanographic?nid=87523 Institution (WHOI) ©  
Edwards, a graduate student in the joint MIT/WHOI program, pointed out that this is not completely the case, because oil is composed of a complex mixture molecules, some of which the microbes are unable to break down.

'Oil is still detrimental to the environment, ' she said, 'because the molecules that are not accessible to microbes persist and could have toxic effects.' These are the kinds of molecules that can get into the food web of both offshore and shoreline environments, Edwards and Van Mooy said. In addition, Edwards added, the oil that is consumed by microbes 'is being converted to carbon dioxide that still gets into the atmosphere.'

Follow-up studies already 'are in place,' Van Mooy says, to address the 'mysterious' finding that the oil-gorging microbes do not appear to manufacture new cells. If the microbes were eating the oil at such a high rate, what did they do with the energy?

Van Mooy, Edwards, and their colleagues hypothesize that they may convert the energy to some other molecule, like sugars or fats. They plan to use 'state-of-the-art methods' under development in their laboratory to look for bacterial fat molecules, a focus of Van Mooy’s previous work. The results, he says, 'could show where the energy went.'

Van Mooy said he isn’t sure exactly what fraction of the oil loss in the spill is due to microbial consumption; other processes, including evaporation, dilution, and dispersion, might have contributed to the loss of the oil slick. But the five-fold increase in the microbe respiration rate suggests it contributed significantly to the oil breakdown.

'Extrapolating our observations to the entire area of the oil slick supports the assertion microbes had the potential to degrade a large fraction of the oil as it arrived at the surface from the well,' the researchers say in their paper.

'This is the first published study to put numbers on the role of microbes in the degradation of the oil slick,' said Van Mooy. 'Our study shows that the dynamic microbial community of the Gulf of Mexico supported remarkable rates of oil respiration, despite a dearth of dissolved nutrients,' the researchers said.

Edwards added that the results suggest 'that microbes had the metabolic potential to break down a large portion of hydrocarbons and keep up with the flow rate from the wellhead.'

Also participating in the study from WHOI were researchers Christopher M. Reddy, Richard Camilli, Catherine A. Carmichael, and Krista Longnecker.

The research was supported by RAPID grants from the National Science Foundation.

Woods Hole Oceanographic Institution website

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.




by Woods Hole Oceanographic Institution

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=87523

10:45 PM Sat 20 Aug 2011 GMT






Click here for printer friendly version
Click here to send us feedback or comments about this story.


News - USA and the World





































ISAF Sailing World Championships - Watch medal races live here by Dan Ibsen, Sail-World Europe & UK editor,








470 Men and Women Worlds - Vadlau and Ogar into pole position by 470 International Association Class,




ISAF Sailing Worlds, Santander - Strong competition for RS:X fleets by Olga Maslivets, International RS:X Class Assoc.,


















America’s Cup: The Future is foiling – AC45s to be modified
Volvo Ocean Race: Win a stopover trip by designing an ECsix T-Shirt
Red Bull 49erFX: On the eve of the Worlds in Santander
America's Cup: Ben Ainslie Racing launches partnership with Yamaha
2014 Chicago Match Cup - Starts tomorrow
Rio 2016 Daylight the issue for Olympic sailing regatta
ISAF Sailing World Championships - USA 470's and Lasers battle at top
ISAF Sailing World Championships - Santander - Day 5 video highlights
ISAF Sailing World Championships - Santander images by Jesús Renedo
PWA Cold Hawaii World Cup - No action on day 2
470 Men and Women Worlds - Game on for Olympic Qualification
ISAF Sailing World Championships: Finns off to slow start in Santander
ISAF Sailing World Championships - Seesaw Day 5 in Santander + Video
ISAF Sailing World Championships - 470 sailors shine in Santander
Royal Cup Marina Ibiza - Kiwi Ray Davies returns to TP52 fleet
Starboard Hatteras Wave Jam - No windsurfing action on day 1
A complete recap of the most successful Melges 20 World Championship
Rolex Big Boat Series - Prizegiving images by Chuck Lantz
ISAF Santander - Upwards path for Austrian women's 470 crew + video
18ft skiffs: Carnage compilation from the glory days of the Grand Prix
ISAF Worlds: Video from the British Sailing Team   
Bart's Bash expected to set new records this weekend   
PWA Cold Hawaii World Cup - Marcilio Browne wins Super Session   
470 Men and Women World Championships - Racing abandoned on day 2   
ISAF Sailing World Championships - Day 4 images from Santander   
ISAF Sailing Worlds, Santander: Emerging Nations Program sailors shine   
ISAF Sailing Worlds, Santander - Teasing winds play havoc on day 4   
ISAF Sailing World Championships: Hot conditions in Santander on day 4   
Santander ISAF Sailing World Championships joins Bart’s Bash   
PWA Cold Hawaii World Cup - Grounded fishing boat creates problems   
Marseille One Design - GC32 Armin Strom Sailing Team emerge victorious   
Rolex Big Boat Series 2014 - Ready for another 50 years   
2014 Rolex Big Boat Series - Farr 40 Day 4   
2014 Rolex Swan Cup - Eleventh-hour victories   
Extreme Sailing Series - Kiwis clinch Act win in Istanbul + Video   
2014 Rolex Big Boat Series - Two long races today for the J70 fleet   
2014 Rolex Big Boat Series - Impressive to sail out of the Golden Gate   
Extreme Sailing Series - Istanbul delivers four days of great racing   
ISAF Sailing Worlds Santander - Day 3 images by Sail-World.com   
Extreme Sailing Series: Emirates Team NZ bounces back for series win   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW US
LocalAds   DE  ES  FR  IT