Community-level impacts induced by introduced largemouth bass and bluegill in farm ponds in Japan
Community-level impacts induced by introduced largemouth bass and bluegill in farm ponds in Japan
复制标题
日本农场池塘引进大口黑鲈和翻车鱼对社区造成的影响
DOI：
10.1016/s0006-3207(02)00144-1
复制
发表时间：
2003
影响因子：
5.9
通讯作者：
T. Miyashita
中科院分区：
文献类型：
--
作者：
Y. Maezono;T. Miyashita
大口黑鲈Micropterus salmoides和蓝鳃鱼Lepomis macrochirus已被引入许多国家，并已成为世界性的外来物种。然而，只有少数研究表明它们对引进社区的影响。为了研究它们的影响，我们在日本东部琦玉县的15个农场池塘进行了自然快照实验。我们选择了10个和5个小池塘在类似的环境条件下，但与和没有外来物种，分别。在发现外来物种的池塘中，鱼类、甲壳类和若虫的数量较小，一些物种被认为在几个池塘中已经灭绝。另一方面，底栖生物，即蝌蚪，摇蚊，chaoborids，寡毛类的数量更丰富的池塘与外来物种。这两类生物在DCA的第一轴上分离明显，表明这种差异主要是由鲈鱼捕食引起的。这一结果表明，营养级联中，自上而下的影响引起的外来传播的鱼类，甲壳类和若虫的odonates直接和一些底栖生物间接。因此，当一个是保护本地生物，不仅要注意直接的负面影响，而且还应注意传播到各个营养级的间接影响。由于农场池塘是典型的日本小静水系统，具有丰富的生物多样性和鲈鱼和蓝鳃鱼已被证明改变农场池塘社区广泛，保护治疗，包括消除外来鱼类应立即进行。
Largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus have been introduced into many countries and have become cosmopolitan exotic species. However, only a few studies show their impact on introduced communities. To investigate their impact, we performed natural snapshot experiments in 15 farm ponds in Saitama prefecture, eastern Japan. We selected 10 and 5 small ponds in similar environmental conditions, but with and without exotics, respectively. The numbers of fish, crustaceans, and nymphal odonates were smaller in ponds where exotics were found and some species were considered to be locally extinct in several ponds. On the other hand, the numbers of benthic organisms, i.e. tadpoles, chironomids, chaoborids, and Oligochaeta were more abundant in ponds with exotics. These two groups of organisms were separated clearly on the first axis of DCA, which indicats that this difference was mainly induced by bass predation. This result suggests a trophic cascade in which top-down effects induced by exotics propagated to fish, crustaceans, and nymphal odonates directly and to some benthic organisms indirectly. Therefore, when one is to conserve native organisms, attention should be paid not only to direct negative effects, but also to indirect effects propagating to various trophic levels. Because farm ponds are typical Japanese small lentic systems having rich biodiversities and bass and bluegill have been shown to change farm pond communities widely, conservational treatments including eradication of exotic fish should be conducted immediately.