Seasonal dynamic of fish communities in the Three Gorges Reservoir of the Yangtze River, China.

Shaorong Yang, Huanzhang Liu, Mingzheng Li

Monday 29 june 2015

17:45 - 17:48h at Europe 1 & 2 (level 0)

Themes: (T) Hydro-environment, (ST) Ecohydraulics and ecohydrology, Poster pitches

Parallel session: Poster pitch: 3G. Environment - Ecohydraulic

To investigate impacts of reservoir impoundment on fish communities, the monthly investigation on fish communities in the Mudong and Wanzhou sections in the Three Gorges Reservoir (TGR) of the Yangtze River, China were conducted from June 2007 to October 2008. The Mudong section is at the end of the TGR where the environment is still river-like, while the Wanzhou section is in the middle of the TGR and the water is much stagnant. A total of 38 species were found in Mudong section and 58 species in Wanzhou section during the investigation period, and there were significant differences in the fish compositions between these two sections. Rheophilic species such as Coreius guichenoti, Gobiobotia filifer, Pelteobagrus vachelli, Pelteobagrus nitidus, C. Heterodon and Saurogobio dabryi were the dominant species in the Mudong section. And the fish species endemic to the upper reaches of the Yangtze River accounted for a certain proportion in this section. In contrast, the Wanzhou section were dominated by limnophilic species such as Hemiculter bleekeri, Cyprinus carpio, Carassius auratus, Hemiculter leucisculus, and Hypophthalmichthys molitrix. Besides, several exotic species were found in Wanzhou section. For both these sections, the Margalef index (D) and Shannon-Wiener index (H_) were higher in low water seasons than in other seasons, and Pielou’s evenness index (J_) was stable through all the time. The multivariate analysis of the monthly samples indicated a significant seasonal change in the fish community. And our analysis indicate different seasonal dynamic of fish communities in different sections of the TGR, and therefore the different impacts of the reservoir impoundment.