Study on the Efficiency and Influencing Factors of Xiniu Fishway in the Lianjiang River

The Xiniu Fishway in Guangdong Province was the first fishway added to a major dam in southern China. To investigate the effectiveness of this fishway, the web method and plugging method were employed for a total of 12 times from January to December in 2013. In total, 41 species of fish, belonging to 33 genera, 9 families and 4 orders, were captured. Small-sized species, such as Squalidus argentatus, Microphysogobio kiatingensis and Rhinogobius giurinus, were dominant. The fish number and species differed greatly between seasons and were significantly higher in April, May and June than in other months. A hierarchical scaling of the fish community in different months separated the communities into three clusters:group Ⅰ occurred in January, February, March, September and October; group Ⅱ in April, May, June, July and August; and group Ⅲ in November and December. The index of fish diversity (H') ranged between 0.83 and 1.95, with the maximum value for August and the minimum value for January. The index of fish species richness (D') ranged between 0.93 and 3.00, with maximum and minimum values for May and January, respectively. Redundancy analysis was used to describe the relationship between the fish community and associated environmental factors in each month. Water velocity, runoff, dam level and water transparency all impacted the success of the fishway (P < 0.05).