Incidence of Salmincola californiensis in Westslope Cutthroat Trout in Relation to Brook Trout Density in the Lolo Creek Drainage

Abstract

The objective of my study was to discover if the density of invasive Brook trout had an effect on the incidence of native Westslope Cutthroat trout infected by Salmincola californiensis. The study was conducted under a United States Fish and Wildlife collection permit while electro fishing in the Lolo Creek drainage in northwestern Montana. Streams in the Lolo Creek drainage were sampled and trout densities and infection incidence were quantified. A linear regression test was performed to test for significant associations. A significant negative correlation was observed between the Brook trout density and the incidence of Salmincola californiensis infection in Westslope Cutthroat. Brook trout are effective at reducing the amount of Saslmincola californiensis infected Westslope Cutthroat trout. My study showed an invasive species aiding a native species.