Abstract: No perceptible differences in morphology and anotamy except angles between leaf and stemamong three populations of Spartina anglica from England (Lancashire,Essex and Poole Har-bour) were observed.However,marked differences were found in their ultrastructural changes,proline accumulation and pattern changes of MDH and POD isozymes under various stresses.With all findings we come to the conclusion:three ecotypes have been emerging:Poole har-bour ecotype,Lancashire ecotype and Essex ecotype.The primary ecotypical differentiation ofSpartina anglica is of great importance in selecting of more tolerant and highly productive eco-types with adaptation to various ecological conditions.

Key words: Algae, Simulation stabilization pond, Purification, Water quality