Decreased streamflow impacts fish movement and energetics through reductions to invertebrate drift body size and abundance
Decreased streamflow impacts fish movement and energetics through reductions to invertebrate drift body size and abundance
复制标题
水流减少会减少无脊椎动物漂流体的大小和丰度，从而影响鱼类的运动和能量
DOI：
10.1002/rra.3340
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发表时间：
2018
影响因子：
2.2
通讯作者：
S. Chandra
中科院分区：
文献类型：
--
作者：
T. Caldwell;G. Rossi;René E. Henery;S. Chandra
径流驱动生态过程跨越多个营养水平，使其成为“主变量在lotic系统。”在山区系统中，特别是那些受管制的山区系统，干旱频率的增加和积雪的减少可能会改变未来的径流状况，并影响生态过程。我们监测无脊椎动物漂流丰度，大小和多样性作为径流的函数。然后，我们将这些变量的鱼类运动和精力充沛的效率在沙斯塔河上游在加州，上面和下面的一个大的分流。无脊椎动物漂流生物量显着减少，在受损的流量与未受损的流量相比，无脊椎动物的平均身体大小随着流量的减少而减少。一般来说，鱼的运动是更大的受损流网站（>50%的时间鱼被跟踪）。鱼类运动在上游网站是负相关的个别猎物项目的大小和数量的猎物，并没有检测到显着的驱动程序在流受损的网站。当搜寻觅食发生时，能量效率降低了70%以上，并且在低流量期间能量摄入的净速率低于0 J/s。我们的研究结果表明，鱼类觅食行为可能会间接影响通过改变无脊椎动物漂移的数量和大小的流量。转向觅食行为，加上食物供应不足，导致能量效率下降。未来的处方流量调节河流应占季节性时间尺度上的无脊椎动物漂移，鱼类行为和鱼类能量学的变化。
Streamflow drives ecological processes across multiple trophic levels making it a “master variable in lotic systems.” In mountain systems, especially those that are regulated, increased frequency of droughts and reductions in snowpack may alter future streamflow regimes and impact ecological processes. We monitored invertebrate drift abundance, size, and diversity as a function of streamflow. We then related these variables to fish movement and energetic efficiencies in the Upper Shasta River in California, above and below a large streamflow diversion. Invertebrate drift biomass was significantly less at impaired flows compared with unimpaired flows, and average body size of invertebrates decreased with decreasing streamflow. Generally, fish movement was greater at the impaired flow site (>50% of the time fish were tracked). Fish movement at the upstream site was negatively related to the size of individual prey items and amount of prey available, and significant drivers were not detected in the flow‐impaired site. Energetic efficiency was reduced by over 70% when search foraging took place, and the net rate of energetic intake was below 0 J/s for low‐flow periods. Our results suggest that fish foraging behaviour may be influenced indirectly by altered streamflow through changes to amount and size of invertebrate drift. A shift to foraging behaviour, coupled with low food availability, results in decreased energetic efficiency. Future prescriptions of flow rates to regulated rivers should account for changes to invertebrate drift, fish behaviour, and fish energetics on seasonal time scales.
影响因子：
2.6
作者：
M. Power;Keith Bouma‐Gregson;Patrick Higgins;S. Carlson
通讯作者：
M. Power;Keith Bouma‐Gregson;Patrick Higgins;S. Carlson