Oral Presentation International Conference on River Connectivity (Fish Passage 2018)

Development of a fish passage inventory and evaluation of success rates of major fish passages on fish movements through barriers in regulated river systems of China (#32)

Jinlong Liu 1 , Giri Kattel 2 , Zhongjing Wang 1 , Mengzhen Xu 1
  1. Tsinghua University, Beijing, BEIJING, China
  2. University of Melbourne, Melbourne, Victoria

Many river systems in China are highly regulated. The ecosystems structure and functions of these river systems are threatened by barriers such as irrigation and hydropower dams restricting fish movements for reproductive and food habitats. To overcome this challenge, several fish passages are built. However, the inventory and potential of fish passages are not well investigated. In this study, we have developed a fish passage inventory by identifying the type, the location and time, we have then evaluated the effectiveness or success rates of fish passage types. Out of 222 fish passage facilities are in use globally, 73 fish passages are in China, where the pool-type fishways are accounted for 87.7%, followed by nature like and lifting type, each accounted for 4.1%. We evaluated the lifting height to slope ratios of a fish passage is a function of success rates for fish passing through the barrier. Among 24 pool-type fishways analyzed, slope tended to decrease with increasing lifting heights and showed potential implications for fish movements through the barriers. The Changzhou Fishway (Peral River) and the Cuijiaying Fishway (Yangtze River) showed greater potential of fish crossings. Forty species of fish successfully passed through the Changzhou Fishway from 2011 to 2014, where four species, Pelteobagrus vachelli, Squaliobarbus curriculus, Hemiculter leucisculus and Anguilla japonica made the successful crossing, with 29.1%, 16.8%, 14.7%, and 12% respectively. From the Cuijiaying Fishway, eleven species made a successful passing in 2012 alone, in which three species Pelteobagrus vachelli, Hemiculter leucisculus and Distoechodon tumirostris made 46%, 16% and 13% successful crossings. When many dams in China are facing critical challenges to adopt the right type of fish passages, the pool-type fishways with variable adjustments of lifting heights to slopes could be a good option for successful fish crossing in regulated river systems.