The Dale Hollow National Fish Hatchery is a fish hatchery administered by the United States Fish and Wildlife Service located in Clay County, Tennessee, in the United States. It mitigates losses of fishery resources caused by the construction of federal government dams as part of water development projects in the southeastern United States by raising brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), lake trout (Salvelinus namaycush), and rainbow trout (Oncorhynchus mykiss) and stocking them in affected waters. It also engages in the conservation of threatened and endangered freshwater non-game fishes and freshwater mussels.
Activities Trout production
The Dale Hollow National Fish Hatchery uses the Strategic Habitat Conservation (SHC) framework to manage fisheries resource priorities. It provides brook trout (Salvelinus fontinalis), brown trout (Salmo trutta), lake trout (Salvelinus namaycush), and rainbow trout (Oncorhynchus mykiss) for mitigation stocking – i.e., to compensate for lost fishery resources – in Tennessee. Bodies of water the hatchery has stocked for population loss mitigation purposes in Tennessee include J. Percy Priest Lake and its tailwater in the Stones River; the Center Hill Reservoir tailwater in the Caney Fork River; the Wolf River; the Dale Hollow Reservoir and its tailwater in the Obey River; the Normandy Reservoir tailwater in the Duck River; the Tims Ford Reservoir tailwater in the Elk River; the Appalachia Reservoir tailwater in the Hiwassee River; the Norris Reservoir tailwater in the Clinch River; the Tellico Reservoir; the Tellico River; the Calderwood Reservoir; the Chilhowee Reservoir; and a number of reservoirs and/or their tailwaters on the Holston River, namely the Cherokee Reservoir tailwater, the Fort Patrick Henry Reservoir and its tailwater, the South Holston Reservoir and its tailwater, the Wilbur Reservoir and its tailwater, the Watauga Reservoir, and the Boone Lake tailwater.
In addition to its mitigation work in Tennessee, the hatchery supplies fish to mitigate the negative effects of United States Government dam construction as part of water development projects in northern Georgia. In exchange for striped bass (Morone saxatilis) eggs and fry from the Gulf Coast of the United States, it also provides rainbow trout to Alabama to restore the population in the tailwater of the Lewis Smith Reservoir in the Sipsey River. On a reimbursable basis, the hatchery also provides a limited number of rainbow trout for non-mitigation stocking in the Red River in Tennessee near Fort Campbell under a cooperative agreement with the Tennessee Wildlife Resources Agency.
The Dale Hollow National Fish Hatchery does not spawn trout; instead, it receives fertilized trout eggs via overnight shipments from other hatcheries and places them in incubator trays. After the fry hatch, the hatchery staff places them in indoor tanks, where they receive food and care until they reach a length of . The staff then transfers the trout to outdoor raceways, where they remain until they are about 18 months old and have reached a length of . Hatchery personnel then weigh and harvest the fish and load them onto trucks which transport them to stocking sites or other hatcheries. The hatchery draws its water from the Dale Hollow Reservoir at a depth at which the water remains at a temperature of between year-round; as of 2000, the hatchery drew this water from a depth of , but as of 2017 this had increased to . The water undergoes aeration to ensure it contains sufficient dissolved oxygen before it is pumped into the hatchery's tanks and raceways. In 2000, water flowed through the hatchery at a rate of per minute; by 2017, this had increased to per minute.
Threatened and endangered species
In addition to its work with trout, the hatchery assists in the recovery and restoration of threatened and endangered freshwater species including non-game fishes and freshwater mussels. It develops propagation and culture techniques for such species, and releases the animals it raises into the wild to either reestablish populations in waters where they have become locally extinct or to augment existing wild populations of them.
Barrens topminnow A particular focus of the hatchery is the preservation and reestablishment of the extremely rare Barrens topminnow (Fundulus julisia), which is native only to springs and spring-influenced streams on the Barrens Plateau in south-central Tennessee. During fiscal year 2016 (October 1, 2015–September 30, 2016), the hatchery distributed 69 Barrens topminnows hatched in 2012 to a stocking site located on private property in Warren County, Tennessee, and accepted from the Tennessee Aquarium 123 Barrens topminnows hatched in 2015 from the Elk River population, which the hatchery held as an "ark" population.
Freshwater mussels Beginning in fiscal year 2000 (October 1, 1999–September 30, 2000), the Dale Hollow National Fish Hatchery took part in a three-year freshwater mussel culture project designed to transfer mussel culture technology from the Tennessee Cooperative Fishery Research Unit to the U.S. National Fish Hatchery System, specifically to the Dale Hollow facility in Tennessee and the Wolf Creek National Fish Hatchery in Kentucky. The hatchery attempted to grow juvenile mussels in closed, recirculation systems while feeding them algae grown in trout egg hatching jars. Like other mussel-holding facilities, the hatchery had problems keeping juvenile mussels alive for prolonged periods so that they could grow to a sufficient size to be reintroduced to natural waterways.
The hatchery renewed its mussel culture effort in 2013, partnering with the United States Army Corps of Engineers, Tennessee Cooperative Fishery Research Unit (Unit), United States Fish and Wildlife Service Ecological Services Field Office, Tennessee Wildlife Resources Agency, and Friends of Dale Hollow National Fish Hatchery as well as the Natchitoches National Fish Hatchery in Louisiana in a new project that attempted to culture mussels in cages suspended in the Dale Hollow Reservoir, allowing them to filter their own food naturally from the water rather than being fed algae. In the project, the TWRA employed electrofishing techniques from boats in April 2013 to collect spotted bass (Micropterus punctulatus) from the reservoir for use as hosts for glochidia (microscopic parasitic mussel larvae which infest the gills of host fish). The fish were transported to the hatchery where, two weeks later, Tennessee Cooperative Fishery Research Unit personnel infested half of them with glochidia of the mucket (Actinonaias ligamentina, genus Actinonaias) and half with glochidia of the pink mucket (Lampsilis abrupta). Three weeks later, the host fish were moved from the hatchery to Dale Hollow Reservoir, where they were placed in cages suspended beneath a U.S. Army Corps of Engineers boathouse. Over the next three weeks, the glochidia transformed into juvenile mussels and settled into sand at the bottom of the cages, after which the former host fish were released into the reservoir. The mussels grew in the cages for another five months until October 2013, when they were harvested, the harvest yielding 22 muckets, eight pink muckets, and four non-endangered plain pocketbooks (Lampsilis cardium) which apparently had infested the host fish prior to their capture the previous April. The mussels displayed surprising growth while in the cages during this first trial. The harvested mussels were sent to the Ohio River Islands National Wildlife Refuge to help in the recovery of populations severely affected by a 1999 chemical spill.
A second culture trial began in the spring of 2014 when TWRA electrofishing boats again collected spotted bass from Dale Hollow Reservoir and the Eagle Bend State Fish Hatchery provided walleye (Sander vitreus) to the Dale Hollow National Fish Hatchery. Using somewhat altered water quality management procedures, Tennessee Cooperative Fishery Research Unit personnel infested the spotted bass with glochidia from the pink mucket and the walleye with glochidia from the black sandshell (Ligumia recta). The host fish were placed in suspended cages beneath the boathouse in May 2014. In addition, a cage containing saugers (Sander canadensis) infested with black sandshell glochidia and maintained at the lab at Tennessee Technological University was suspended, as was a cage containing pink mucket juveniles placed directly onto the sand substrate. After four months, the mussels were harvested in September 2014, with the staff noting that some of the sand substrate had washed out of the cages. The harvest yielded 601 black sandshell juveniles, mostly from the sauger cages, but no pink muskets. The harvested mussels again went to the Ohio River Islands National Wildlife Refuge.
As of 2015, the hatchery planned to conduct a third trial, using black bass and walleye as host fish for black sandshell and pink musket glochidia and experimenting with means of preventing sand from washing out of the cages. Harvest was expected in September or October 2015, with harvested mussels again to be used in the ongoing Ohio River Islands National Wildlife Refuge restoration and recovery efforts. By 2023, the hatchery was experimenting with raising 14 species of freshwater mussel, and it harvested 2,865 mussels that year, including Duck River dartersnappers (Epioblasma ahlstedti), sheepnose mussels (Plethobasus cyphyus), round hickorynuts (Obovaria subrotunda), pale lilliput pearlymussels (Toxolasma cylindrellus), rough pigtoes (Pleurobema plenum), pink muckets, Cumberland moccasinshells (Medionidus conradicus), and purple cat's paws (Epioblasma obliquata).
Other activities The hatchery assists Native American tribal governments in managing fisheries resources on tribal lands. It also works with the Tennessee Wildlife Resources Agency to ensure a thorough, perennial hatchery product evaluation program.
The hatchery engages in various outreach activities, providing recreational fishing opportunities through Project Healing Waters — a program for wounded members and veterans of the United States Armed Forces — and environmental education opportunities. It also maintains a pollinator garden for the benefit of migrating monarch butterflies (Danaus plexippus).
History The U.S. Army Corps of Engineers completed the Dale Hollow Dam on the Obey River in 1943. The dam created the Dale Hollow Reservoir, a deep lake in which water stratifies into layers with differing temperatures each summer. Water released downstream into the Obey River comes from a deep, cool layer, replacing the warm-water environment that had prevailed in the tailwater below the dam prior to the dam's construction with a cold-water environment, with a negative effect on the game fish populations in the tailwater.
The Dale Hollow National Fish Hatchery was established in 1965 on land leased from the U.S. Army Corps of Engineers just below the Dale Hollow Dam to raise brown, lake, and rainbow trout and stock them in the Dale Hollow Reservoir tailwater in the Obey River to mitigate population losses resulting from the dam's construction, as well as to produce fish for other reservoirs and their tailwaters. By 2000, the hatchery was distributing 1.5 million brown, lake, and rainbow with a total weight of in Tennessee and neighboring states. By 2017, the hatchery was producing of trout, which it distributed both for mitigation purposes and, to a limited extent, for non-mitigation of some waters under cooperative agreements with other agencies. During the 21st century, the hatchery also has assisted in preservation and recovery efforts for endangered populations of non-game fish and freshwater mussels.