Growth tests upon marine microalgae can provide important information about factors limiting algal growth, and bioavailability of nutrients, and can be used as indicators of the water trophic state and toxicity levels. This study was aimed at assessing the quality of the Regione Campania (Italy) coastal waters through algal bioassays with the marine chlorophyta, Dunaliella tertiolecta. Superficial waters were sampled monthly, from October to December 2000, in 22 stations along the Campania shoreline, with the objective to evaluate the environmental trophic state and likely chronic toxicity. Experimental results showed eutrophication and high toxicity effects in the northern part of the study area, particularly, near the Garigliano, Volturno and Sarno rivers. The growth response of microalgae to nutrient addition indicated phosphorus as limiting factor in the proximity to river mouths, probably as a result of the high nitrogen load carried by rivers, and nitrogen in all other stations. In our study microalgal test cultures have proven to be a sensitive chronic toxicity assay and a useful tool to evaluate the "health" of marine coastal waters by allowing their classification into quality categories.

cited By 5