Different phytoplankton stoichiometry and nutrient status in the reservoirs of Fujian Province, China

Abstract

Reservoirs have experienced varied degrees of eutrophication in recent years as the effects of climate change and human activities on reservoir ecosystems have intensified. This study looked at the patterns of integrated nutrient status and total phosphorus (TP) concentration in 30 reservoirs in major reservoirs across Fujian Province. Significant connections were identified between TP concentration, trophic status, and total phytoplankton density. 88.9% of the reservoirs were at the middle trophic level by the nutritional status (EI). The average EI of the 25 reservoirs with water supply functions is 39.2, eight reservoirs in coastal areas having EI values more than 45.0. The EI of the Baisha Reservoir in Jiulong River Basin reached 50.3, indicating modest eutrophication. TP concentration levels in the 30 reservoirs of Fujian Province range from 0.01 to 0.08 mg·L⁻¹, representing different functional categories. Algal bloom is more likely to occur in a reservoir with a high nutrient status value. The N/P mass ratios of the 30 reservoirs were all significantly greater than 7.0, with the minimum is 11.0 and the maximum is 136.0, which indicating that these reservoirs were typically phosphorus-limited.