Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

In Gulf Of Mexico, microbes thrive above natural oil seeps

26.01.2016

New insight into how plankton and oil interact

In the water above natural oil seeps in the Gulf of Mexico, where oil and gas bubbles rise almost a mile to break at the surface, scientists have discovered something unusual: phytoplankton, tiny microbes at the base of the marine food chain, are thriving.


Tiny bubbles of oil and gas rise from mile-deep vents on the seafloor. When they burst at the surface, the oil spreads into patches of rainbow sheen the size of dinner plates. A new study finds microbes near the surface are benefiting from turbulence that accompanies the rising bubbles.

Credit: AJIT SUBRAMANIAM /COLUMBIA UNIVERSITY

The oil itself does not appear to help the phytoplankton, but the low concentration of oil found above natural seeps isn't killing them, and turbulence from the rising oil and gas bubbles is bringing up deep-water nutrients that phytoplankton need to grow, according to a new study appearing in the latest issue of Nature Geoscience. The result: phytoplankton concentrations above oil seeps are as much as twice the size of populations only a few kilometers away.

"This is the beginning of evidence that some microbes in the Gulf may be preconditioned to survive with oil, at least at lower concentrations," said Ajit Subramaniam, an oceanographer at Columbia University's Lamont-Doherty Earth Observatory and coauthor of the study. "In this case, we clearly see these phytoplankton are not negatively affected at low concentrations of oil, and there is an accompanying process that helps them thrive. This does not mean that exposure to oil at all concentrations for prolonged lengths of time is good for phytoplankton."

The study is the first to demonstrate this kind of teleconnection between the sea floor, subsea floor and microbial processes in the upper ocean, said Andy Juhl, an aquatic ecologist at Lamont and coauthor. It also provides insight into how microbes and oil interact under water, he said.

Subramaniam and Juhl, along with colleagues in the Ecosystem Impacts of Oil and Gas Inputs to the Gulf (ECOGIG) consortium, began studying interactions around oil seeps after the Deepwater Horizon oil well disaster in 2010, to better understand what happens to oil during catastrophic gushers and to find ways to better respond to similar disasters in the future. The natural seeps, found in many parts of the Gulf of Mexico, are tiny compared to an oil-well blowout. An oil slick from a natural seep lasts between one and seven days and reaches between 1 and 100 square kilometers. In comparison, the surface oil from the Deepwater Horizon well covered about 11,200 square kilometers and persisted for months, Subramaniam said. But natural seeps still produce enough oil and gas that the scientists can smell it at the surface and see the oil bubbles burst.

In the lab, Juhl has been conducting experiments to understand how different concentrations of oil affect different types of phytoplankton. He has found no amount of oil on its own that has a positive effect on phytoplankton. "The direct effect of oil is usually negative, but in some cases small amounts of oil can be outweighed by the positive effect of the nutrients that are tagging along," Juhl said.

Lead author Nigel D'Souza, then a postdoctoral researcher at Lamont, discovered the phytoplankton response to oil seeps while on a ship in the Gulf of Mexico monitoring chlorophyll fluorescence - energy that is emitted as light by compounds inside phytoplankton cells used for photosynthesis. Each time the ship crossed over a known oil seep, he noticed a spike in phytoplankton abundance. It was a eureka moment, Juhl said. The evidence backed up what Susan Phan, a coauthor and Columbia University student working on her senior thesis with Subramaniam, had previously noticed in remote-sensing data. The scientists were able to compile multiple lines of evidence through chlorophyll fluorescence, water sampling and satellite images that all supported the idea that phytoplankton were benefitting from something connected with the seeps, even though the seeps were thousands of feet below.

The biggest impact was seen a few hundred feet deep in the water column, at the point where phytoplankton have enough light from above to still grow, and are receiving the most nutrients rising from below. Over oil seeps, D'Souza found that the population was about double the usual amount. The measurements also showed increases in phytoplankton abundance at the surface.

There are still many questions. For example, scientists don't yet know which types of phytoplankton are thriving over the seeps, or if some types of phytoplankton in the community are negatively affected by the rising oil. Previous studies have subjected phytoplankton to oil in laboratories to test their sensitivity and found differences in the impact on oceanic vs. coastal phytoplankton and differences when phytoplankton were in nutrient-rich or nutrient-poor water, as well as damage to some phytoplankton cells at various concentrations of oil.

The microbe community at the surface is also complex and includes oil-degrading bacteria and other microbes. The increase in phytoplankton could, for example, be affected by the impact of oil on bacteria that compete with phytoplankton for nutrients, the authors write.

"Satellite radar data have given us a detailed picture of where natural seeps are concentrated across deep seafloor of the Gulf of Mexico," said co-author Ian MacDonald, an oceanographer and professor at Florida State University. "Building on this, the present, novel results show biological effects near the ocean surface in areas where seeps are most prolific."

Subramaniam and Juhl plan two pathways of study next: to analyze the behavior of different types of phytoplankton above seeps to better understand how they interact with oil, and to improve understanding of how oil from deep underwater rises to the surface.

###

The study was part of the ECOGIG Consortium, a multi-institutional group that studies natural oil seeps in the Gulf of Mexico, funded by the Gulf of Mexico Research Initiative. The other coauthors on the study were Mark Hafez, Alexander Chekalyuk, and Beizhan Yan of Lamont-Doherty Earth Observatory; and Sarah Weber and Joseph Montoya of Georgia Institute of Technology. D'Souza is now a postdoctoral fellow at Georgia Institute of Technology.

The paper, "Elevated surface chlorophyll associated with natural oil seeps in the Gulf of Mexico," is available from the authors.

Contact:

Ajit Subramaniam -- (845) 365-8641 ajit@ldeo.columbia.edu

Andy Juhl -- (845) 365-8837 andyjuhl@ldeo.columbia.edu

More information: Kevin Krajick, Senior editor, science news, The Earth Institute kkrajick@ei.columbia.edu 212-854-9729

The Earth Institute, Columbia University mobilizes the sciences, education and public policy to achieve a sustainable earth. http://www.earth.columbia.edu.

Lamont-Doherty Earth Observatory is Columbia University's home for earth science research. Its scientists develop fundamental knowledge about the origin, evolution and future of the natural world, from the planet's deepest interior to the outer reaches of its atmosphere, on every continent and in every ocean. http://www.ldeo.columbia.edu | @LamontEarth

Kevin Krajick | EurekAlert!

More articles from Ecology, The Environment and Conservation:

nachricht How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>