Response Of Brook Trout (Salvelinus Fontinalis) Populations To Habitat Conditions And Competition In Southern Appalachian Streams

Brook Trout (Salvelinus fontinalis) were largely extirpated from the southeastern Appalachian Mountains in the late 19th and early 20th centuries. Following this collapse, non-native S. fontinalis from northern hatcheries were stocked along with Rainbow (Oncorhynchus mykiss) and Brown Trout (Salmo trutta). I conducted a study comparing the growth and age-class structures of 13 Brook Trout populations across western North Carolina in the presence or absence of non-native salmonids along with environmental co-variates such as pH and elevation. The average size and age of Brook Trout was higher in sympatric streams compared to populations in allopatric streams, but sympatric populations exhibited increased variability. The average size and age of Brook Trout in both allopatric and sympatric populations appeared to increase with elevation. Habitat variables (PCA scores) were used in Generalized Linear and Generalized Linear Mixed models to examine their effects on mean age and length, as well as age-class structure of sympatric and allopatric Brook Trout populations. AIC and AICc scores revealed that no models were more informative than the null. Despite the lack of significant results, this study suggests that environmental factors including elevation and water chemistry may be more important to Brook Trout growth than competition with non-native salmonids.