Effects of Nutrients on Algae Blooms with In-Situ Incubation in Three Lakes of Wuhan in China

Nutrient has been considered to be undoubtedly one of the key factors stimulating algae growth. By a series of experiments the relationship between nutrient elements and phytoplankton growth was explored in three lakes: Lake Yezhihu, Lake Tangxunhu and Lake Nanhu, located in Wuhan City, China. We undertook 5 days in-site incubation experiments in the late April, 2007. The results showed that the chlorophyll a production consistently responded positively to the addition of phosphorus, while responded to the addition of nitrogen were miner by comparison, and phosphorus would be the limited factor of algae growth in Lake Tangxunhu and Lake Nanhu. In the base of nitrogen and phosphorus addition, Fe and Mn all stimulated algae growth in the three lakes, Cu also did in Lake Nanhu, whereas Zn inhibited algae growth in all three lakes, and Cu also did in Lake Tangxunhu. The farther results indicated that algae growth was limited by nitrogen in Lake Yezhihu, phosphorus was also an important nutrient to build biomass of phytoplankton. If it was supplied with both nitrogen and phosphorus at the same time, the algae growth increased sharply.