Every year, millions of eggs fill the tank room at Erwin National Fish Hatchery, incubating until they are strong enough to go to their new home. Erwin NFH is part of the National Broodstock Program, which provides certified disease-free salmonid eggs to federal, state, and tribal hatcheries. Erwin NFH is currently the country's largest non-commercial producer of trout eggs, and produced 19,336,861 eggs from three strains of rainbow trout and one strain of brook trout in the 2024-2025 spawning season.
Spawning begins every year in mid-July, when the Erwin-Arlee strain of rainbow trout begin to produce eggs. In early October, the hatchery wraps up the Erwin-Arlee hybrid strain, and transitions to spawning the Arlee strain of rainbow trout and the Sandwich strain of brook trout. The brook trout and the Arlee strain wrap up in early December, and then the hatchery spawns the Fish Lake strain of rainbow trout from mid-January through early April.
After spawning the eggs are taken to the tank room at Erwin NFH until they reach the "eyed" stage in development. When the eggs are eyed they are strong enough to survive the shipping process, and are ready to be sent to other facilities for hatching and grow-out. Prior to shipping any dead eggs are removed using a machine called a Jensorter, and then the eggs are carefully packed into coolers and boxed up to head to their new home.
Many of the eggs produced at Erwin NFH are sent to other federal hatcheries in the southeast region to fulfil mitigation requirements for the Army Corps of Engineers and the Tennessee Valley Authority. The hatchery also produces trout eggs for state and tribal hatcheries to support recreational fishing opportunities in the southeast and all across the country.