Comparison of phosphorus fraction in eutrophic lake sediments from the northern hemisphere.

Lake sediments are subjected to intensive anthropogenic activities such as dumping of industrial waste water and leakage of P fertilisation from agricultural lands. There has a great body of research focusing on examining phosphorus fractions, which provide fundamental data that facilitate understanding the risk of P-induced eutrophication. Here, we have extracted the data of P fractions from 484 sediment samples residing in 48 lakes mainly in EU, China and USA. NH4Cl-P and total phosphorus (TP) displayed a well linear relationship, but not applicable to all lakes. Six groups were categorised as per the slope and intercept by using the clustering analysis. Specific measures were recommended to curb P release risk by considering the characteristics of each group. For instance, TP controlling is deemed as a priority in group with steep linear dependence of NH4Cl-P on TP. A significant correlation was determined between TP and NaOH-P (r2 = 0.63). Among other findings, larger lake area significantly contributes to lower all P pools. Deeper depth could only pronouncedly influence the BD-P, HCl-P. Additionally, we found lakes in Germany have pronounced higher averaged P pools than other regions. Furthermore, this paper creates awareness of the present status of lake eutrophication for researchers and policy-makers. [ABSTRACT FROM AUTHOR]