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

America's Cup: Group agrees to co-operate in London Meeting by Richard Gladwell/Sail-World.com/nz,














America's Cup: Alameda makes overtures on Venue hosting for San Fran *Feature by Richard Gladwell/Sail-World.com/nz,














































2014 Pacific Cup - Scarlet Runner wins by Vanessa Yates, Hawaii






BIC Techno 293 Worlds 2014 - Day 6
PWA Fuerteventura Grand Slam - Wind teases competitors on day 2
Women’s Match Race Golfe du Morbihan - Action-packed day of racing
Herreshoff Marine Museum announces successful fundraising campaign
Brewin Dolphin Commodores' Cup - The most comprehensive victory yet
Anna Tunnicliffe holds fourth at mid-point of Reebok CrossFit Games
2014 29er North American Open Championship - Australians win
INSA Sabot II Invitational Regatta - Erik Hou claims victory
CMRC Summer Invitational Series - Maxi Soh wins Doubleheader A event
International Moth World Championships - Nathan Outteridge wins
PWA Fuerteventura Grand Slam - First blood to Toselli and Angulo
Melges 24 Nationals - Record entries for 2014 and 2015 venue revealed
Women’s Match Race Golfe du Morbihan - Anna Kjellberg claims the lead
Jessica Uniack Memorial Beach to Bay Race at Long Beach YC
Laser Radial Men’s World Championship - Poland tops the leaderboard
America's Cup - Four teams confirm full support regardless of venue
Plastic Classic takes place at Mariposa Hunters Point YC
Six Metre European Championship - No champion declared for 2014
J/Teams sail tough Chicago Mackinac Race
Anna Tunnicliffe wins first event of Reebok Cross Fit Games + Video
2014 Pacific Cup - Skill and luck required for victory   
Six Metre European Championship - Action resumes on day 4   
BIC Techno 293 Worlds 2014 - Day 4   
PWA Fuerteventura Grand Slam on the horizon   
Rolex Big Boat Series - Golden Jubilee to take place this September   
DH Pacific Cup - Running with the pack + Video   
Women's Match Race Golfe du Morbihan - Testing day in Vannes   
Brewin Dolphin Commodores' Cup - Ireland establishes solid lead   
International Moth Worlds: Outteridge charges into the lead + Video   
Marina Rubicón Round Canary Islands Race - First blood to Team Brunel   
ISAF Youth Match Racing Worlds - Competition heats up on day 2   
Laser Radial World Championships - Competition aplenty on day 3 +Video   
Extreme Sailing Series - Penultimate Act to take place in Nice   
Leukemia Cup - Images by Leighton O'Connor   
Maxi Yacht Rolex Cup - Meeting of the grand designs   
29er North American Championship - Final series kicks off   
29er World Championship 2014 set to start in Kingston, Ontario   
Barcelona and Parnu chosen for 2015 ORC championship events   
2014 Race for Rady Yacht Race - Benefiting Rady Children’s hospital   
CMRC Summer Invitational Series - Doubleheader events start tomorrow   


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