We investigated the effects of aqueous extract from litter of Spartina alterniflora with different concentrations( 0,0.02,0.04,0.10 mg·L~(-1)) on the growth and physiological characteristics of Skeletonema costatum. The cell concentration of S. costatum,chlorophyll-a content,antioxidant enzyme( superoxide dismutase and peroxidase) activities and malondialdehyde content were examined. Moreover,we isolated and identified the algicidal allelochemicals from S.alterniflora. The results showed that the inhibitory...