132-134Growth rates of 3 phytoplankters - Asterionella japonica, Synechocystis sp. and Chlorella sp.- were studied as a function of urea by enriching the nutrient-depleted water with varying concentrations (0 to 50 µg- at N/litre) of urea; growth rate was calculated from the increase in chlorophyll a content of the organisms. Maximum growth of these phytoplankters was observed between concentrations 1 and 2 µg-at urea-N/litre
