连江西牛鱼道过鱼效果及其影响因子研究

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

连江西牛鱼道是我国华南地区首座在水坝主体加建的过鱼通道。为了解其过鱼效果,于2013年1—12月采用张网法和堵截法对西牛鱼道过鱼种类、数量及其环境因子进行12次监测,共监测到鱼类41种,属4目9科33属,通过鱼道的鱼类以银鮈(Squalidus argentatus)、乐山小鳔鮈(Microphysogobio kiatingensis)、子陵吻鰕虎鱼(Rhinogobius giurinus)等小型鱼类为优势种群。不同季节鱼道过鱼种类和数量差别较大,4—6月过鱼种类和数量显著高于其他月份。对不同月份鱼道鱼类群落进行聚类分析(CLUSTER),可以将其分为3个类群。过鱼生物多样性指数8月最高、1月最低;丰富度指数5月最高、1月最低。对各月份采集的鱼类群落与水文因子进行冗余分析(RDA),发现流速、流量、上游水位和透明度这4个因子对过鱼效果影响显著(P<0.05)。

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:groupⅠoccurred in January,February,March,September and October;groupⅡin April,May,June,July and August;and groupⅢin 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).