Does stocking of filter-feeding fish for production have a cascading effect on zooplankton and ecological state? A study of fourteen (sub)tropical Chinese reservoirs with contrasting nutrient concentrations
Does stocking of filter-feeding fish for production have a cascading effect on zooplankton and ecological state? A study of fourteen (sub)tropical Chinese reservoirs with contrasting nutrient concentrations
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DOI：
10.1007/s10750-014-1896-3
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发表时间：
2014-05
期刊：
影响因子：
2.6
通讯作者：
Qiuqi Lin;Xiaojun Jiang;B. Han;E. Jeppesen
中科院分区：
文献类型：
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作者：
Qiuqi Lin;Xiaojun Jiang;B. Han;E. Jeppesen
由于自然补充量低，放养滤食性鱼类是中国水库增加鱼类产量的常用手段。这种放养是否对浮游动物有重要的负面影响，对浮游植物有级联效应，这是有争议的。比较了14个不同营养盐浓度和鱼类密度的水库浮游动物群落。叶绿素a（Chla）和渔获量与总磷（TP）呈正相关，而浮游动物生物量没有表现出类似的关系与TP。浮游动物似乎是受鱼类的影响，因为高的鱼类渔获量与低比例的桡足类生物量的总calanoids，轮虫的总浮游动物生物量的高比例，低的浮游动物：浮游植物生物量的比例，以及水蚤的情况下，无论TP浓度。浮游动物生物量和大多数浮游动物：浮游植物生物量的比例是最低的文献中所报道的营养范围研究。此外，Chla：TP比率高于温带湖泊中通常观察到的比率。我们的结论是，自上而下的控制浮游动物是在中国南方的水库，频繁放养的滤食性鱼类似乎有助于以较高的藻类生物量和清晰度降低的形式水质差的关键。
Stocking of filter-feeding fish is a common tool used in Chinese reservoirs to increase fish production because of low natural recruitment. Whether such stocking has important negative effects on zooplankton with cascading effects on phytoplankton is debated. We compared the zooplankton communities in fourteen reservoirs with different nutrient concentrations and fish densities. Both chlorophyll a (Chla) and fish catch were positively related with total phosphorus (TP), whereas zooplankton biomass did not show a similar relationship with TP. Zooplankton seemed to be influenced by fish as high fish catches coincided with a low proportion of calanoids of the total copepod biomass, a high proportion of rotifers of the total zooplankton biomass, a low zooplankton:phytoplankton biomass ratio, and the absence of Daphnia irrespective of TP concentration. Both zooplankton biomass and most of the zooplankton:phytoplankton biomass ratios were among the lowest reported in the literature for the nutrient range studied. Furthermore, the Chla:TP ratio was higher than what is typically observed in temperate lakes. We conclude that top-down control of zooplankton is of key importance in reservoirs in South China where frequent stocking of filter-feeding fish seems to contribute to poor water quality in the form of higher algal biomass and reduced clarity.