Effects of common carp on nutrient dynamics and littoral community composition: roles of excretion and bioturbation
Effects of common carp on nutrient dynamics and littoral community composition: roles of excretion and bioturbation
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DOI：
10.1127/1863-9135/2007/0168-0027
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发表时间：
2007
影响因子：
1
通讯作者：
Shin‐ichiro S. Matsuzaki;N. Usio;N. Takamura;I. Washitani
中科院分区：
文献类型：
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作者：
Shin‐ichiro S. Matsuzaki;N. Usio;N. Takamura;I. Washitani
我们操纵通过围隔实验的存在和不存在的小鲤鱼（鲤鱼，L）和他们的沉积物访问使用网眼网。实验的目的是确定鲤鱼的营养动态和社区组成的影响，并部分分离生物扰动的影响，其余鲤鱼的影响，如排泄和捕食。在这两个月里，鲤鱼影响水质和营养动态，改变浮游植物的生物量和组成和沉水植物生物量下降独立的沉积物访问，表明营养排泄的鲤鱼影响的主要机制。然而，Secchi深度下降，而悬浮固体的浓度增加时，鲤鱼进入沉积物被允许，这表明鲤鱼的生物扰动影响水的透明度。浮游植物（占主导地位的蓝藻）和悬浮固体的增加导致沉水植物生物量减少，通过减少光的可用性。浮游动物，轮虫占主导地位，增加鲤鱼外壳。此外，底栖大型无脊椎动物减少鲤鱼外壳，无论存在和不存在的网。由于直接捕食效应不明显，鲤鱼可能会影响底栖大型无脊椎动物通过减少沉水植物。这些结果表明，鲤鱼可以通过排泄和生物扰动对营养动态和沿岸的群落结构产生显着的直接和间接影响。因此，鲤鱼的生态系统工程可能会引发从以沉水植物为主的清水状态到以浮游植物为主的浊水状态的转变。
We manipulated through an enclosure experiment the presence and absence of small common carp (Cyprinus carpio, L) and their sediment access using a mesh net. The aims of the experiment were to determine carp effects on nutrient dynamics and community composition, and partially separate bioturbation effects from the remaining carp effects such as excretion and predation. During the two months, carp influenced water quality and nutrient dynamics, altered phytoplankton biomass and composition and decreased submerged macrophyte biomass independently of sediment access, indicating that nutrient excretion was the primary mechanism for the carp effects. However, Secchi depth decreased while the concentration of suspended solids increased when carp access to the sediments was allowed, suggesting that bioturbation by carp influenced water transparency. Increase in phytoplankton (dominated by cyanobateria) and suspended solids resulted in reduced submerged macrophyte biomass through reduction of light availability. Zooplankton, numerically dominated by rotifers, increased in carp enclosures. In addition, benthic macroinvertebrates decreased in carp enclosures, regardless of the presence and absence of the netting. Because direct predation effects were not evident, carp probably affected benthic macroinvertebrates through reduction of submerged macrophytes. These results indicate that carp can have dramatic direct and indirect impacts on nutrient dynamics and littoral community structure through excretion and bioturbation. Ecosystem engineering by carp may therefore trigger a shift from a clear water state dominated by submerged macrophytes to a turbid water state dominated by phytoplankton.