Plumes of plankton blooms wins New Zealand’s top science prize

Dr Strzepek (left) receives his award from New Zealand Prime Minister John Key.

Robert Strzepek, a visiting scientist in the Research School of Earth Sciences, has won the New Zealand Prime Minister’s Science prize.

Strzepek is part of a team of researchers from the National Institute of Water and Atmospheric Research and the University of Otago in New Zealand who have taken out the $500,000 award.

The nine-member team has been investigating the potential role the ocean has in influencing climate change over the past one million years. They examined how manipulating the oceans to remove carbon dioxide could mitigate or help solve global warming.

Strzepek, who will join ANU permanently as a research fellow in January 2012, said the win came as a total surprise.

"We are all very passionate about what we do, and never expected this kind of recognition. Having said that, it is immensely satisfying and humbling to receive it," he said.

"Our team focuses on understanding the role that microscopic marine plants, known as phytoplankton, have on modulating earth’s climate. In the geological past phytoplankton have played a significant role in the large swings in atmospheric carbon dioxide levels.

"As a phytoplankton physiologist, I specialise in understanding how the availability of iron affects phytoplankton photosynthesis and therefore their ability to grow. During these experiments I constantly monitored the health of these organisms and also collected some so that we could continue our research back in the lab. This can be tricky, as they don’t like the warm Australian weather. It’s kind of like trying to grow a banana in the Antarctic.

"Iron is an essential nutrient for these plants and our team was the first to perform large-scale iron fertilisation experiments in the Southern Ocean.  Greater supply of iron relieves the ’anaemia’, or blood deficiency, that usually restricts phytoplankton growth and the capacity for carbon dioxide drawdown. Indeed, the extent of these blooms was so spectacular they were visible from space."

Strezepek said that large-scale iron fertilisation has been put forward as a potential geo-engineering solution to reducing green house gases. However, the process also came with associated risks.

"Our results demonstrate that the outcome of iron enrichment of the ocean was fraught with other risks and side-effects. These included the release of other even more potent greenhouse gases - such as nitrous oxide, that would offset, and perhaps even cancel out any benefit of enhanced phytoplankton growth soaking up more carbon dioxide. In this case, there is no such thing as a quick fix," he said.

Strzepek and the rest of the research team were presented with their awards in a ceremony in Auckland on Friday, 16 December.