Marine eutrophication: A proposed data analysis procedure for assessing spatial trends

A methodology for the discrimination of the different trophic levels at a s patial scale in the marine environment is proposed using spatial analysis m ethods and non-parametric statistics. Phytoplankton cell number, being a re presentative parameter to express trophic trends in the marine ecosystem is selected for the methodology development; Saronicos Gulf, Greece is used f or the case study. The proposed stepwise methodology includes interpolation for assessing the spatial distribution of phytoplankton cell number, divis ion of the Gulf into a number of quadrates, development of a scale characte rising trophic levels and finally characterisation of the trophic state of each quadrate using non-parametric statistics. The advantages of this metho dology and the potential applications in coastal management studies are als o discussed.