汀江中上游鱼类多样性及其影响因子

基于2012-2013年的2、5、7、10对汀江中上游河流水域的6个江段的调查数据,探讨鱼类多样性的时空差异以及鱼类组成与环境因子间的关联。共采集鱼类71种,隶属4目15科54属,其中福建省保护动物1种、福建省特有种4种;优势种有宽鳍鱲Zacco platypus、黄颡鱼Pseudobagrus fulvidraco、银鮈Gnathopogon argentatus 3种;常见种有马口鱼Opsariichthys bidens等12种。鱼类多样性指数(香农指数)在站位间和季节间差异均显著。根据典范对应分析(CCA)对鱼类群落与环境因子间关联进行了分析,结果显示:水温和人类活动是决定鱼类群落分布的主导因子,总氮、溶解氧、高锰酸盐指数、底质、堤岸稳定性、植被多样性和河道变化在决定鱼类群落分布上也有一定作用。人类活动的加剧不仅改变了汀江中上游物种组成(即洄游性、敏感性地方物种减少,而外来物种、广布耐受性鱼类增多),也降低了该河流鱼类的物种多样性。

Factors Affecting Diversity of Fish Species in Mid-and Upper-streams of Tingjiang River

Correlations among the habitat conditions,diversity of fish species,and human activities were studied using the data collected from 6 locations on the mid-and upper-streams of Tingjiang River in February,May,July, and October from 2012 to 2013. The results showed that the 71 fishes caught belonged to 4 orders,15 families,and 54 genera.They included the provincial protected species,such as Mastacembelus armatus ,the endemic species, Pseudogastromyzon fasciatus ,Pseudogastromyzon cheni ,Crossostoma stigmata and Crossostoma fascicauda ,and the dominant species,Zacco platypus ,Pseudobagrus fulvidraco ,and Gnathopogon argentatus ,along with 12 commonly found species.Based onthe one-way ANOVA,the Shannon-Wiener indices on samples collected from the 6 locations varied significantly.The indices for fish caught at Xinqiao were higher than other localities,with significant seasonal variations.The canonical correspondence analysis (CCA)indicated that the determining factors on the composition and distribution of the fishes in the two sections of the river were water temperature and human activities,while the substrates on the river bed,changes of river channel,stability of bankment,vegetation,as well as the total nitrogen content and permanganate index of the water,also contributed significantly to the diversity and distribution.The human activities along the river not only altered the composition of fish,such as the reduction on the migrotory and endemically specialized species and the increase on the invasive and tolerant species,but also decreased the diversity in the mid-and upper-streams of the Tingjiang River.