PATTERNS IN THE IMPERILMENT OF NATIVE FRESHWATER FISHES OF GEORGIA
The southeastern United states is a hotspot for biodiversity of native fishes. Georgia ranks third in the U.S. in native fish species richness. This area has a high rate of imperilment caused by human-induced degradation of stream habitats. Degraded habitats favor a few species, and studies have suggested that certain taxa are more susceptible to imperilment than others based upon life history traits or habitat preference. This study investigated the relationship between imperilment and family, substrate preference, stream size, and flow preference to determine if there are patterns of extinction or endangerment for rare fishes of Georgia. Data was collected from fish status assessment maps of rare fishes constructed by the Georgia Department of Natural Resources Nongame Section based upon fish detections over a >20-year sampling period. Imperilment was classified into five categories based on the number of years since the species was last observed in a watershed, and a weighted imperilment score was developed for each species based upon the ratio of historically-occupied watersheds and currently-occupied watersheds. This study found a significant difference in imperilment score among family (p = 0.013), flow (p = 0.002), and substrate (p = 0.011). Results suggest that imperilment risk is similar among each category except that Fundulidae and Cyprinidae differ from each other, slow and moderate flow differ from swift flow, and vegetation differs from large substrate. Based upon our study, taxa that are more susceptible to imperilment include those fishes that prefer slower flows, which may be susceptible to stream alterations that create homogenized stream habitats that eliminate pools and increase sedimentation. This data may help predict losses of fish diversity, guide recovery efforts, and identify fishes that are indicators of ecological health.
Howington*, Mark; Cox*, Caroline; and Henson*, Darrien
"PATTERNS IN THE IMPERILMENT OF NATIVE FRESHWATER FISHES OF GEORGIA,"
Georgia Journal of Science, Vol. 77, No. 1, Article 94.
Available at: https://digitalcommons.gaacademy.org/gjs/vol77/iss1/94