FISH USE OF ARTIFICIAL DIKE STRUCTURES IN A NAVIGABLE RIVER

Artificial structures have been used to potentially increase fish production by providing cover, feeding and spawning areas. In some rivers, the United States Army Corps of Engineers has constructed dikes to provide additional habitat for river fishes and to mitigate for navigation impacts to young fishes. This study was designed to test whether such structures function as viable habitats as evidenced by increased abundances relative to reference areas lacking artificial dike structures. Dikes and reference sites in the Kanawha River, West Virginia were sampled 21 times between July 2002 and October 2003. We found a difference in taxonomic composition among fish using dikes relative to reference areas. Artificial dike structure use was most important among Centrarchidae species, especially juveniles, including black bass and several species of Lepomis. Further, distribution of fish between areas with and without dikes appears most affected by water temperature in 2002 and by short-term river flow in 2003. These patterns suggest these artificial structures are viable mitigation measures that target and benefit fish of economic interest. Copyright (C) 2009 John Wiley & Sons, Ltd.