Abstract:Based on the survey data in Enteromorpha prolifera outbreak area of the Yellow Sea during July 9-14,2008, distribution patterns of temperature, salinity, dissolved oxygen (DO), nutrients and their relationships with green tide were studied. The results showed that DO was oversaturated for nearly all the stations, averaged 9.22 mg/L. Generally, DO showed lower values in southern area and higher values in northern area, lower in eastern area and higher in western area. Average concentration of dissolved inorganic nitrogen (DIN) was 9.07 mol/L. The DIN values in northern area were lower than in southern area, and that in offshore area were lower than in northern Jiangsu coastal area. Average concentration of phosphate was 0.19 mol/L, with a decreasing trend from the east to the west and from the open sea to the Haizhou Bay. The higher nutrient values were found in the eastern survey area. It was observed that temperature, salinity, DO, nutrient values were suitable for the growth and spore release of E.prolifera. In a large accumulation area of E.prolifera, the average concentrations of DIN (14.89 mol/L) and phosphate (0.27 mol/L) were higher than the other areas. It was indicated that adequate nutrients were the material base for green tide. Meanwhile, the average N/P ratios at the surface layer, ten meters layer and bottom layer were 702, 194 and 411, respectively, higher than the Redfield value. Most investigated waters were subjected to potential phosphorus limitation.
