Population growth patterns of Skeletonema costatum and nutrient levels in the lower East River,New York,U.S.A.

The population growth patterns of Skeletonema costatum and nutrient levels in the lower East River were examined through field measurements and laboratory experimentation. Maximum growth rates of this diatom (approximately 1.8 divisions per day) were obtained in water samples from the late winter-early spring months. Summer water samples supported little or no growth of this diatom. Measurements of NH₃-N, PO₄,-P, and Si in water samples from the lower East River indicated that nutrient saturated conditions exist year round in this area. The effect of toxic substances in the water column may be responsible for limiting S. costatum growth during the summer months.