For the last 14 years, the Tennessee Aquarium Conservation Institute and its partners have been working diligently to rear Lake Sturgeon in captivity and reintroduce them into the Tennessee River. For the last three years, we have worked with Conservation Fisheries Incorporated to breed endangered Conasauga Logperch in captivity and augment their populations in Tennessee and Georgia. This year, TNACI was awarded a grant from the National Fish and Wildlife Foundation to create a new propagation program.
Photo of a Southern Appalachian Brook Trout in its natural environment. Photograph by Dave Herasimtschuk.
Southern Appalachian Brook Trout (SABT) in Tennessee and North Carolina are distinct from the Brook Trout found elsewhere in the United States because they have been geographically isolated from their northern relatives for thousands of years. They are under threat from habitat degradation and invasive species introduction. Historically, they lived in cool, fast flowing streams in the southern Appalachian Mountains. Logging and agricultural practices, however, have decimated Appalachian forests, which in turn harm the waters where brook trout live. When surrounding forests are lost from creeks, water temperature rises, oxygen levels drop, and siltation from erosion increases, all resulting in streams that can no longer support brook trout. In addition, introduced populations of rainbow trout, brown trout, and even northern brook trout compete with native SABT for the most high quality habitat. In the Southeast, only 3% of historic watersheds support SABT populations.
Conservation measures for this fish have been underway over the last few years at other hatcheries in the Southeast. However, we at TNACI are attempting to take a different approach. In general, trout hatcheries (and hatcheries for other fish) operate on flow-through systems. When TNACI was located in Cohutta, GA, our Lake Sturgeon were in a flow-though system. While this is energy efficient and has the potential for housing large numbers of fish, disease transfer and escapees can be a problem. This grant will help TNACI develop techniques for rearing SABT in recirculating systems that drastically reduce disease transfer and escape concerns.
With assistance from our partners (Tennessee Wildlife Resources Agency, the U.S. Fish and Wildlife Service, and the U.S. Forest Service) we have collected 50 Brook Trout for brood stock. This is a beautiful fish, especially during the fall when they spawn. All year, the fish have red spots along their sides, and their pectoral, pelvic and anal fins are red with a white leading edge. But when spawning season arrives, the red coloring becomes much more pronounced.
|SABT in July|
|SABT in October|
We have already stripped some of our SABT of their gametes (eggs and sperm). It is a delicate process that involved gently squeezing the trout. Once fish were stripped, 1% saline was added to the eggs and sperm and the solution stirred with a turkey feather. The turkey feather is an old tradition that has been used for decades in fish hatcheries. Now that the eggs have been fertilized they are being held at TNACI until they hatch, which takes about two weeks. We should have babies (larval SABT) very soon!
|Stripping a SABT and taking a fin clipping|
|Fertilized trout eggs|