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Development of a Multimetric Index for Fish Assemblages in a Cold Tailwater in Tennessee
Author(s) -
Ivasauskas Tomas J.,
Bettoli Phillip W.
Publication year - 2014
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1080/00028487.2013.866982
Subject(s) - electrofishing , index of biological integrity , tailwater , environmental science , fish <actinopterygii> , fishery , hypolimnion , index (typography) , fish measurement , fork (system call) , downstream (manufacturing) , hydrology (agriculture) , ecology , biology , oceanography , computer science , geology , geotechnical engineering , nutrient , world wide web , eutrophication , operating system , operations management , economics
Tailwaters downstream of hypolimnetic‐release hydropeaking dams exhibit a unique combination of stressors that affects the structure and function of resident fish assemblages. We developed a statistically and biologically defensible multimetric index of fish assemblages for the Caney Fork River below Center Hill Dam, Tennessee. Fish assemblages were sampled at five sites using boat‐mounted and backpack electrofishing gear from fall 2009 through summer 2011. A multivariate statistical approach was used to select metrics that best reflected the downstream gradients in abiotic variables. Five metrics derived from boat electrofishing samples and four metrics derived from backpack electrofishing samples were selected for incorporation into the index based on their high correlation with environmental data. The nine metrics demonstrated predictable patterns of increase or decrease with increasing distance downstream of the dam. The multimetric index generally exhibited a pattern of increasing scores with increasing distance from the dam, indicating a downstream recovery gradient in fish assemblage composition. The index can be used to monitor anticipated changes in the fish communities of the Caney Fork River when repairs to Center Hill Dam are completed later this decade, resulting in altered dam operations.