Effect of Instream Sand Dredging on Fish Communities in the Kansas River USA: Current and Historical Perspectives

ABSTRACT

Relatively few studies have examined the ecological effects of instream sand and gravel mining which occurs in many streams and rivers worldwide. The objective of this study was to evaluate fish community composition at sand dredged and unmodified (control) sites in the Kansas River, Kansas. Fish and habitat sampling were conducted at two control sites and one dredged site in September 1979 and 1980. The same sites and one additional dredged site were sampled in September 2006. In 2006, dredged sites were deeper and had slower current velocities than control sites. Similarity indices determined that fish community at control sites in 2006 were 80% similar to the same sites in 1979 and 1980, despite 26 years between sampling. Dredged sites had more variable species composition, but one site still had large-river species (blue sucker shovelnose sturgeon), which were sampled above the actual dredge in fast shallow water. Native river fish species were similarly present in 1979–1980 and 2006, but lentie and non-native fishes (e.g., centrarchids), although still in low abundance, increased in 2006 particularly in dredged sites. These results suggest that sand dredging provided habitats that were suitable for lentic fishes, but other anthropogenie effects (reservoir construction urbanization) also likely contributed to fish assemblage changes in the Kansas River