Fractionation and Determinants of Sediment Nitrogen and Phosphorus in the Algae-Dominated Moon Bay of Lake Taihu (China)

Li, X.; Zhao, Y.; Han, R., and Wang, G., 2021. Fractionation and determinants of sediment nitrogen and phosphorus in the algae-dominated Moon Bay of Lake Taihu (China). Journal of Coastal Research, 37(3), 506–517. Coconut Creek (Florida), ISSN 0749-0208.Sediment nutrients are sensitive to environmental fluctuations. The frequent migration and transformation of sediment nutrients result in different fractions. Studying the relationships between favorable nutrient fractions and the benthic environment is critical for understanding the contributions of C, N, and P and their geochemical cycles. In total, nine sediment cores were collected for the study of spatiotemporal distributions of C, N, and P in sediments of Moon Bay, Lake Taihu (China). Pearson correlation and principal component analysis were performed to analyze the influence of environmental parameters and seasons on the concentration of sediment nutrient fractions. Results showed that the algal Moon Bay was phosphorus dominated, given the light total phosphorus loading (401.86 mg/kg). The great concentration gradient from sediment to overlying water (493 times) favored the phosphorus release. Dissolved oxygen, organic loading, and sediment depth showed a close relationship with the mineralization process, which was directly controlled by the reduction-oxidation potential. As the temperature increased, the mineralization could be enhanced. The lower total organic carbon to total nitrogen ratio in summer (16.37) than winter (30.5) verified the strong decomposition and mineralization with the help of active microorganisms. This study provides a reference to understand the influence of physicochemical parameters and primary producers on the C, N, and P geochemical cycles in sediments.