Friday, August 30, 2013
- by Shannon L. Colbert
The Southern Appalachian Brook Trout, SABT, is one of the most beautiful aquatic animals in the Appalachian Mountains. These colorful fish seem to herald the coming of autumn as their brilliant red bellies and bright golden spots appear with the change in seasons. “There’s no mistaking Southern Appalachian Brook Trout when they display their breeding colors,” said Dr. Anna George, director of the Tennessee Aquarium Conservation Institute (TNACI). “They are the only native freshwater fish in the Southeast with a primary spawn in the fall.”
Once abundant in the mountain headwaters of East Tennessee, SABT are down to just three percent of their historical range today. Logging activities wiped out large portions of the habitat for this fish. When SABT numbers dwindled, many sites were overtaken by Rainbow Trout, a non-native species that can withstand warmer water and more direct sunlight. “Recent efforts to restore the forested areas along these streams are paying off,” said Dr. George. “So there is an opportunity today to begin recovery work for the Southern Appalachian Brook Trout which is Tennessee’s only native trout.”
The National Fish & Wildlife Foundation awarded a grant to TNACI to participate in a study to perfect captive breeding techniques for this species. There is a significant need to progress captive propagation efforts for this species before the remaining distinct populations decline further in the wild.
TNACI biologists collected 50 brood fish from Hampton Creek, located in Carter County, TN, in October 2012. These adults were brought back to the Tennessee Aquarium in Chattanooga.
Eggs and milt were collected from these brood fish with the help of trout experts from Tennessee Wildlife Resources Agency, TWRA, and U.S. Fish & Wildlife Service, USFWS. Fertile eggs began developing in late October and by the end of November baby trout began hatching marking the first time this species had been successfully reared in a closed-circulation system.
Before this success at TNACI, Southern Appalachian Brook Trout had only been successfully raised at the Tellico Fish Hatchery in the Cherokee National Forest a few times. Their success, using water from the source stream, inspired the idea that TNACI scientists could do the same thing at the Aquarium using chilled and dechlorinated tap water sourced from the City of Chattanooga. Because most hatcheries operate using flow-through water systems, concern exists about the transmission of disease and escaped fish to nearby wild populations.
On Thursday, TNACI biologists returned to Hampton Creek to release 255 juvenile trout with TWRA. “Each fish was implanted with a tiny wire tag,” said Dr. George. “A graduate student from Tennessee Tech University will survey Hampton Creek in January to obtain some baseline information for this project. A handheld detector will tell us which trout were released this summer.”
This first propagation success and release has taken just under one year to achieve. Biologists will begin the whole process again in another month, inching closer to an expanded program that might one day ensure that anglers throughout the region find robust populations of these gorgeous fish.