Kansas has more freshwater fish species than other states in the west and northern US. More than 140 fishes have recently been documented in Kansas rivers; of these, at least five are categorized as endangered species in Kansas (and threatened species in the USA). These endangered species were distributed mainly in northeastern, southwestern, and central Kansas before 1968; however, their occurrence decreased dramatically since 1968 when farming and other landuse change became widespread. In this study, endangered species distribution was analyzed for two periods, historical (pre-1968) and contemporary (1969–2012) using the explanatory variables average annual sediment concentration, daily flow and water temperature, in addition to percentage agricultural land use, urban land use, and the number of impoundments.
Results/Conclusions
All variables were significantly different between historical and contemporary periods. Decreased suspended sediment concentration and temperature were observed in the contemporary period, most likely related to the increased number of impoundments. Dams are known to trap sediments and release cold water from the hypolimnion. Analysis shows a strong correlation between the absence of the five fish species and the number of dams and average daily flow, suggesting that river flow and fish barriers may contribute to species decline. Findings are expected to broaden the understanding of the influence of different water quality parameters, land use/cover change, and fish barriers on the distribution of endangered fish species in Kansas.