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Longitudinal Variation in the Ohio River Fish Community
Author(s) -
Seegert Greg,
Vondruska Joe,
Perry Elgin,
Dixon Doug
Publication year - 2013
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1080/02755947.2013.785990
Subject(s) - electrofishing , species richness , taxon , notropis , ecology , abundance (ecology) , fishery , biology , community structure , geography , fish <actinopterygii>
The Ohio River fish community was sampled three times (June, August, and October) in 2005 by electrofishing near 17 power plants encompassing nearly the entire length of the Ohio River (river kilometer 82–1,527). Six 500‐m zones were electrofished at each plant. Using a generalized additive model, we examined this data set of 306 electrofishing samples to determine how the abundance of 31 taxa varied over the length of the river. We also looked for trends in several measures of community health (catch rate, species richness, index of biotic integrity, and modified index of well‐being). Of the 31 taxa examined, all but three showed longitudinal differences over the course of the river. Based on the patterns for the 31 taxa and 5 community measures, we assigned each taxon or measure to one of seven classes. The largest class included 10 taxa that declined steadily in abundance from upriver to downriver. All community measures followed a similar pattern except that each measure increased near the downstream‐most plant. Conversely, only two taxa (Striped Bass Morone saxatilis and River Carpsucker Carpiodes carpio ) showed the opposite trend (i.e., increasing in a downstream direction). Some taxa were restricted to the upper or lower end of the river or to certain reaches along the river. Species that were restricted to the upper river were primarily stream fishes (certain minnows Notropis spp. and several darters Etheostoma spp.). Conversely, fish species that were restricted to the lower river were primarily large‐river fishes as well as species that were typical of the Mississippi River fauna. Site‐specific differences in water temperature, Secchi depth, specific conductance, and dissolved oxygen were generally unimportant in explaining the observed patterns. Substrate type (percent cobble/boulder and percent silt) occasionally was important. The observed longitudinal trends appeared to be primarily in response to natural temperature and habitat differences between the upper and lower sections of the Ohio River. Received March 16, 2012; accepted March 10, 2013