Phosphorus availability and phosphatase activity in the sediments of Mandovi estuary, Goa

143-144Alkaline phosphatase activity (APA) was measured as the rate of hydrolysis of p-nitrophenyl phosphate (p-NPP). Significant activity was observed in all sediment samples examined. Activity was inversely related to salinity, except in September where exceptionally high activity was observed at the mouth. Phosphatase was induced in response to phosphorus deficient conditions in the water column. Potential phosphatase activity was found to be indicative of the extent and rate of decomposition of organic phosphorus in sediments. In general, high phosphatase activity corresponded to low TP and low IP, but high OP in the sediments