Due to the discharge of nutrients into the East China Sea, severe eutrophication has appeared in Hangzhou Bay. Therefore, we cultivated Gracilaria verrucosa on a large scale in the Jinshan enclosed sea with an area of 1.72 km 2 in the northern part of Hangzhou Bay to perform bioremediation. The Fengxian enclosed sea with an area of 2.3 km 2 and 50 km far from Jinshan was used as the control. The results showed that the Hangzhou Bay was severely eutrophicated before G. verrucosa cultivation. During the period of cultivation between August 2006 and July 2007, the annual growth rate of G. verrucosa was 9.42% day −1 , and the sea water quality was improved from worse than grade IV to grades II-III, with the concentration of dissolved inorganic nitrogen (DIN) and PO 4 -P significantly lower than that in the Fengxian enclosed sea (p< 0.01). The concentration of NH 4 -N, NO 3 -N, NO 2 -N, and PO 4 -P after G. verrucosa cultivation was decreased by 54.12%, 75.54%, 49.81%, and 49.00%, respectively. The density of phytoplankton in the Jinshan enclosed sea with cultivation of G. verrucosa was 6.90-126.53×10 4 cells m −3 , which was significantly lower than that in the Fengxian enclosed sea. In addition, species diversity, richness, and evenness was significantly increased after cultivation of G. verrucosa in the Jinshan enclosed sea compared with that in the Fengxian enclosed sea. The density of Skeletonema costatum, Prorocentrum micans, and Prorocentrum donghaiense, which were the usual species of red tides at the coastal sea of China, in the Jinshan enclosed sea with cultivation of G. verrucosa was significantly lower. Based on these results, if the water quality in the Jinshan enclosed sea were to be maintained at grade I (DIN ≤0.20 mg L −1 ) or II (DIN ≤0.30 mg L −1 ), 21.8 t or 18.0 t fresh weight of G. verrucosa need to be cultivated, respectively. These results indicated that largescale cultivation of G. verrucosa could play a significant role in the bioremediation of Hangzhou Bay.

Surveys of zooplankter and phytoplankton through environmental DNA (eDNA) and metagenomic technology across Dianchi Lake and the estuary of inflowing rivers was conducted, to evaluate the microbial diversity of Dianchi Lake and the estuary of four in flowing rivers. Diversity of plankton and the similarity of dominant species results revealed that the dominant eukaryotic phytoplankton in Dianchi Lake was Bacillatiophyta. The Shannon diversity index values of phytoplankton and zooplankton ranged from 3.68 to 18.36 and 0.54 to 2.49, respectively. The main genus taxa in the Dianchi Lake were similar with the inflowing river. The distribution map of Shannon diversity index gave overall insight into the variation of plankton diversity. The research proved that the eDNA technology was effective in biodiversity monitoring in aquatic ecosystem, and the inflowing river may impose an adverse influence on the ecosystem health of Dianchi Lake.

In recent decades, there are lots of the changes of land use in the Liusha River basin in Xishuangbanna, Yunnan Province. The large-scale replacement of natural forests by rubber plantation have had a certain impact on the ecological environment and water resources in the Liusha River basin. Based on the data of runoff, rainfall and evaporation from 1963 to 2015 measured by Menghai Hydrological Station of Liusha River, the effects of climate change and human activities on the ecological environment of Liusha River runoff and the degree of change were analyzed by using the comparison method of slope change rate of runoff accumulation. The research results show that the cumulative amount of runoff flow after mutation presents significant decrease trend from 1963 to 2015. Because of the Liusha river runoff change decision which residents downstream watershed water security, the runoff of the ecological environment situation and analysis, the protection of natural resources such as forests and the effective protection of regional water resources sustainable development has important guiding significance.