A Naval Service cadet has teamed up with a Galway statistician to assess pollution off the western Irish Sea, writes Lorna Siggins, Marine Correspondent
Hands up - how many fish are there in the sea? How many grains of sand are there on a beach? And how many scientists are working with inadequate tools to analyse the effects of same?
Statistician John Newell of the department of mathematics at NUI Galway is loath to volunteer a quick answer, but a recent project initiated with the Naval Service and the Marine Institute seeks to take a fresh look at statistical models applied to interpret marine research.
The focus of the research project was a 10-year dataset of nutrient levels in the western Irish Sea, which has been collected and maintained by the Marine Institute since 1990. The institute published an initial analysis of a decade's monitoring of winter levels of phosphates, nitrates and silicates in 2002.
The aim of this review was to detect any long-term trends in the levels of these compounds, which might in turn have an impact on the marine ecosystem by affecting plankton production and contributing to water stagnation and eutrophication.
It did identify several "hot spots" where nutrient levels were high, including Dublin Bay, Dundalk Bay, Waterford harbour and Carlingford Lough, Co Louth, but found that there was no evidence of significant nutrient elevation beyond background levels in most coastal and offshore areas along the eastern seaboard.
However, the Marine Institute says it was aware that valuable additional information might be gleaned from the data if more sophisticated statistical tools were applied.
Enter Lieut Brian Mathews (26), a Naval Service cadet from Carrigaline, Co Cork, who is currently executive officer on the LE Róisín. He recently completed a BSc in computer science at NUI Galway. As part of his final year project, Lieut Mathews worked with Newell on examining both existing and new methods for assessing the information.
"Basically, the institute was using salinity regression to look at their data, which involves balancing the inshore and offshore saline environments and accounting for different values," Mathews explains. "We came up with three alternative methods, involving smoothing, nonparametric trend assessment and general additive models to look at the nutrient levels over the period."
As Newell explains, smoothing techniques are used to reduce irregularities or random fluctuations in time series data. "They provide a clearer view of the true underlying behaviour of the series," he says.
Mathews came up with similar results to the existing review of nutrient levels. "We didn't see any significant trend that would lead us to alter the existing conclusions, but there's scope for further work on the same theme - analysing different data," he believes.
It is an offer that could strike a chord with increasingly vocal industry practitioners who are critical of the validity of science underpinning marine management policy. "Lies, damned lies and fishery statistics . . ." as one headline summarised such opinion in a recent edition of the British weekly, Fishing News.
Although the Marine Institute now has two fine research ships that have to earn their keep, the Naval Service has stated that it would be willing to assist in collecting further scientific data in this and other fields as part of its remit to boost the national research effort - while still fulfilling its primary fishery protection role.
Meanwhile, the Marine Institute has teamed up with the University of Wales, Bangor, and the Environmental Protection Agency in Ireland to develop new monitoring techniques and provide integrated physical, chemical and biological oceanographic data for the Irish Sea. The project, entitled MATSIS (Monitoring and Assessment of the Trophic Status of the Irish Sea), funded by the EU, will run from now until 2007.