Evidence of Rainbow Trout Spawning in Small, Warmwater Tributaries of the Chattahoochee River, Georgia

Abstract

We conducted electrofishing surveys for adult and juvenile rainbow trout Oncorhynchus mykiss in small (first- and second-order), warmwater tributaries of the Chattahoochee River, below Morgan Falls Dam, during winter 2004 and 2005 to document spawning. In 2004, we documented pre-spawning males and females in both streams surveyed. In 2005 and 2006, we found juveniles in two of five streams surveyed and pre-spawning adults in three of the five. This is the first documented instance of spawning by rainbow trout in this section of the river and an unusual occurrence in warmwater tributaries. The total contribution of recruitment from these systems to the rainbow trout population in the Chattahoochee River should be evaluated.