Submerged macrophytes facilitate dominance of omnivorous fish in a subtropical shallow lake: implications for lake restoration
Submerged macrophytes facilitate dominance of omnivorous fish in a subtropical shallow lake: implications for lake restoration
复制标题
DOI：
10.1007/s10750-016-2717-7
复制
发表时间：
2016-03
期刊：
影响因子：
2.6
通讯作者：
Jinlei Yu;Zhengwen Liu;Hu He;Wei Zhen;B. Guan;Feizhou Chen;Kuanyi Li;P. Zhong;F. Teixeira-de Mello-F.-Te
中科院分区：
文献类型：
--
作者：
Jinlei Yu;Zhengwen Liu;Hu He;Wei Zhen;B. Guan;Feizhou Chen;Kuanyi Li;P. Zhong;F. Teixeira-de Mello-F.-Te
基于去除粗鱼、鱼群以及有时还种植沉水植物的生物操纵已被用于恢复温带富营养化浅水湖。然而，在温暖的湖泊中，杂食性鱼类数量更多，显然不太受食鱼者的控制。利用肠道内容物分析和基于稳定同位素分析数据的同位素源模型，研究了中国五里湖恢复段鱼类的食物网络结构和能量途径。我们发现，就数量而言，杂食动物在鱼类群落中占据主导地位。一般配合力分析表明，浮游动物的主要食物是环状桡足类，而所有成年杂食性鱼类主要以大型植物为食。IsoSource SIA模型支持这些结果。此外，食鱼者吃虾，而不是幼年杂食性动物，SIA分析显示，食鱼者与成年杂食性动物或浮游动物之间没有营养联系。我们的结论是，大型植物是杂食性动物的重要食物项目，由于食鱼性动物的控制能力较弱，可能会促进杂食性动物的种群增长。这可能会对浮游动物和大型植物产生很高的捕食压力，可能会阻止在富营养化湖泊恢复后建立稳定的大型植物状态，除非定期控制鱼类密度。
Biomanipulation based on removal of coarse fish, piscivorous fish stocking and sometimes also planting of submerged macrophytes has been used to restore temperate eutrophic shallow lakes. However, in warmer lakes, omnivorous fish are more abundant and apparently less well controlled by the piscivores. We investigated the food web structure and energy pathways of fish in the restored part of subtropical Lake Wuli, China, using gut contents analysis (GCA) and the IsoSource model based on stable isotope analysis (SIA) data. We found that omnivores dominated the fish community in terms of numbers. GCA showed that cyclopoid copepods constituted the main food item for the planktivores, while all adult omnivorous fish fed mainly on macrophytes. The IsoSource SIA model supported these results. Furthermore, piscivores consumed shrimps rather than juvenile omnivores, and the SIA analysis revealed no trophic links between piscivores and adult omnivores or zooplanktivores. We conclude that macrophytes constituted an important food item for omnivores, potentially promoting population growth of omnivores as control by piscivores was weak. This may yield a high predation pressure on both zooplankton and on macrophytes, possibly preventing the establishment of a stable macrophyte state following restoration of eutrophic lakes unless the fish density is regularly controlled.