Ian Snape Interview - Special Topic of Oil Spills

Special Topic of Oil Spills Interview, February 2011

Ian Snape

According to our Special Topics analysis on oil spills research over the past decade, the work of Professor Ian Snape ranks at #4 by total number of papers, based on 26 papers cited a total of 233 times. In the Web of Science® from Thomson Reuters, his record includes 59 original articles, reviews, and proceedings papers cited a total of 568 times from January 1, 2000 to January 8, 2011.

Snape is a Geochemist and Principal Research Scientist in the Australian Government's Australian Antarctic Division. He is also the Chairman of the Contaminants in Freezing Ground Network. He is the co-editor of the book Bioremediation of Petroleum Hydrocarbons in Cold Regions (Cambridge University Press, February 2008), and serves as Associate Editor of the journals Cold Regions Science and Technology and Science of the Total Environment.

ScienceWatch.com correspondent Gary Taubes talks with Snape about his highly cited work in the Antarctic.

SW: When did you start working in the Antarctic, and what was the focus of your research?

I've been involved with the Antarctic program since 1998. I've focused on the assessment of contaminated sites and trying to understand the processes by which contaminants move through the environment and how they interact with the biological world.

The idea is that if we can understand the underlying mechanisms for how things move or degrade, what those processes are, we can best design low-cost, sensible interventions. And secondly, if we know how these contaminants are interacting with the biological world, we can make meaningful predictions about impacts and risks. That helps us prioritize what to do. So there are two elements to this research. One is practical so we can respond and do remediation. The other is understanding the impact to the environment so we can work out what we should do, what's important and what's not.

SW: Can you tell us briefly about the Australian Antarctic program in general?

That's a national program that's run through a government department coordinating research in Antarctica. It involves both government institutions doing research and also a range of collaborations throughout the university sector.

The research focus itself has three main themes. There's a terrestrial and near-shore theme. There's a marine, southern ocean focus, and there's a climate processes and change focus as well. It's quite policy focused, by which I mean that the government has decided that the main goals are to protect the Antarctic environment and to understand the role of climate change on Antarctica and the role of Antarctica in climate change.

SW: What is the source of the contaminated ground in the Antarctic, which we tend to think of, perhaps naively, as a pretty pristine environment.

Ian Snape
Ian Snape, B.Sc., Ph.D.

It comes from two sources. One is the fuel used for power stations and for transport. It's transferred usually from ship to station storage-holding facilities and then decanted at the station into a variety of diesel or light diesel power-generating plants. The other is the occasional marine spill when a ship runs aground and sinks. There have been a couple of those in the last 10 to 15 years.

SW: Your two most-cited papers in the Special Topics analysis involve the mineralization of hydrocarbons and petroleum. What's the rationale behind this research?

There are many tens of thousands of cubic meters of petroleum-contaminated soil in Antarctica. There's so much that it would be extremely expensive and environmentally damaging to dig up that soil and remove it or get it treated. In most developed, temperate, and Arctic polar areas, people use bioremediation as a means of breaking down hydrocarbons. The bioremediation usually involves stimulation of microorganisms, often in conjunction with volatilization, which involves stirring the soil to promote volatilization of hydrocarbons.

My research itself was focused not just on understanding how much these contaminants will move through the environment in Antarctica, but also how we might biodegrade fuel spills in this continent without having to actually remove the contaminated soil.

I established a team of researchers, nationally and internationally, who have worked on a range of technologies to look at preventing off-site migration through the use of permeable reactive barriers and then linking those sorts of technologies to bioremediation. And with bioremediation there are a number of challenges peculiar to cold regions—low temperature is the most obvious one.

Microorganisms don't operate as efficiently at low temperatures, so one of the first papers we published was looking at the effects of temperature on how efficiently these microorganisms break down contaminants (Ferguson SH, et al., "Effects of temperature on mineralisation of petroleum in contaminated Antarctic terrestrial sediments," Chemosphere 52[6]: 975-87, August 2003). Just how much suppression do you really get?

SW: Just how much degradation do you really get? And what did you learn? How much degradation did you see?

The results from this study and others have shown that hydrocarbons do degrade even at very low temperatures. In fact, in this paper, we said that you'd still get significant rates of biodegradation even at temperatures below 10 degrees Celsius, which are the sorts of temperatures we get in soils in the summer. That was very promising.

"...the Antarctic is a big place, but the habitats we most care about are actually very, very rare and our impact in those areas is significant."

Subsequent research by us and others found that you still get a bit of biodegradation at temperatures below zero degrees—even at minus five you still get a bit of biodegradation. The conclusion of this science is that it might take bit longer but we still can use bioremediation in Antarctica. We also demonstrated that the natural microorganisms occurring in the soil there are quite capable of degrading fuel.

We also looked at nitrogen. That's the first paper in the list (Ferguson SH, et al, "The effects of nitrogen and water on mineralisation of hydrocarbons in diesel-contaminated terrestrial Antarctic," Cold Reg. Sci. Technol. 37[2]: 197-212, September 2003). Most Antarctic soils are very low in nitrogen, but these microorganisms need nitrogen to grow and to take carbon out of the hydrocarbon to make cells.

So one of those two highly cited papers looked at the effects of temperature and the other looked at the effects of optimizing nitrogen. It's very easy actually to put too much nitrogen in. You want to get just the right amount for these fragile soils.

SW: Do you always have to add nitrogen to these Antarctic soils?

Yes, you do. In fact, the nitrogen is more limiting than the temperature. If you just add nitrogen and let the microorganisms get on with it, they will degrade fuel at quite an accelerated rate. Nitrogen was the biggest limitation to natural processes of biodegradation.

SW: In your opinion, what is it about these papers that has made them so highly cited, so influential?

There are a number of nations with bases in the Antarctic dealing with fuel spills, but I think the reason for the high number of citations is that there are a lot of people working in the Arctic, where contamination is much more extensive. It's a much bigger market, in effect, in the Arctic and they know about bioremediation and use it much more extensively up there.

SW: How has your research evolved in the seven years since those two papers were published?

The research has advanced in a number of areas. One of the big things we're doing is focusing on early intervention in a fuel spill by the introduction of permeable reactive barriers. One of the ideas there is to look at sequenced barriers. Imagine three treatment zones, where you have a nutrient-release zone, a hydrocarbon-capture zone, and then a sort of nutrient-mop-up-and-capture zone.

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