Microbial Succession and Its Mechanism during an Algal Bloom Event in Three Gorges Reservoir
Lei Zhang, National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in TGR Region ( WEMST), China, [email protected]
Chuan Zhou, Southwest University, [email protected]
Zhiqiang Xia, University of Windsor, [email protected]
G. Doug Haffner, Great Lakes Institute, Univ. of Windsor, [email protected]
Subba Rao Chaganti, University of Windsor, [email protected]
Paul Hamilton, Canadian Museum of Nature, [email protected]
Jiupai Ni, Southwest University, [email protected]
Abstract
An intact harmful algal bloom (HMB) event was witnessed from April 10 to May 17, 2015 in Pengxi River, the largest tributary in north shore of Three Gorges Reservoir, China. 7 transections from upstream to estuary were sampled averagely every 7.6 days in the duration. In each transection, the water column's profiles of temperature, DO, turbidity and chlorophyll a (Chl-a), respectively, changing with depth were monitored by logger. Water samples from 0.5m depth of each transection were analyzed for phytoplanktonic cell density and community, 16S and 18S DNA high throughput, TN, TP, DTN and DTP. The results show that HAB happened within the thin epilimnetic layer of upstream in the tributary. Temporal difference is greater than spatial. The synchronization of Chl-a and DO indicated the onset of the algal bloom, and lowering DO while Chl-a remaining high implied HAB descent caused by fungi and boosted predators mainly composed of obtrumia. The high turbidity and temperature, depleted DO led to the end of HAB and and beginning of re-dominating of phytoplankton.
1. Keyword
harmful algal blooms
2. Keyword
bioindicators
3. Keyword
eutrophication
4. Additional Keyword
Three Gorges Reservoir
5. Additional Keyword
Biological succession
6. Additional Keyword
Environmental factors