Effects of Channelization on Fish Biomass in River Ecosystems  

作　　者：Scott S. Knight R.F. Cullum F.D. Shields Jr. P.C. Smiley 

机构地区：[1]USDA-ARS National Sedimentation Laboratory, Oxford 38655, MS, USA [2]USDA-ARS-Soil Drainage Research Unit, Columbus 43210, OH, USA

出　　处：《Journal of Environmental Science and Engineering(A)》2012年第8期980-985,共6页环境科学与工程（A）

摘　　要：Channel straightening in a naturally meandering river is a common historical trigger of channel incision which typically results in stream bank destabilization. Several of the larger river systems in the upland portion of the Yazoo River Basin have subjected channelization resulting in profound changes in the physical and geomorphological characteristics of these systems. Fish were sampled using electroshocking gear and hoop nets to evaluate the impact of stream bank destabilization and loss of habitat heterogeneity resulting from channelization on fish communities. While distinct differences in the fish communities were evident, only the Skuna appeared to have characteristics of a damaged system. More than 95% of the biomass was comprised of species reaching an adult length of less than 300 mm. The lotic omnivorous fishes that dominated the biomass from Skuna are often associated with smaller streams rather than rivers. Furthermore, 72% of the catch consisted of fish preferring littoral zone habitats. The shallow depth and lack of woody debris in Skuna provided a selective advantage for smaller species of fish that could use shoreline habitats as protection from the current. Based on results from the Skuna River, channel straightening that leads to channel incision, bank failure and over widening provide habitats too shallow to support a community of fishes typical of northern Mississippi riverine system. This information may be useful in making comparison of damaged riverine ecosystems and assist managers in determining impairment and success in the TMDL （Total Maximum Daily Load） process.

关 键 词：Channel incision channel straightening fish biomass. 

分 类 号：X522[环境科学与工程—环境工程] S931.5[农业科学—渔业资源]