Lanesboro, MN – Governor Mark Dayton recently requested $130 million for natural resources preservation in his new 2018 public works bill. Of the requested funds, $13 million is slotted for state hatchery improvement. The DNR’s flagship hatchery in Lanesboro would receive $5 million for infrastructure repair and new equipment installation.
Lanesboro Hatchery is the state’s primary trout facility, producing over 100,000 pounds of trout every year. The hatchery consists of an office, a garage, a house for the manager, an egg collection building, a nursery, many raceways, and two rearing ponds. Annually, 450,000 brown trout fingerlings, 24,000 brown trout yearlings, 85,000 rainbow trout fingerlings, and 200,000 rainbow trout yearlings are released into Minnesota waters.
“Biologists continually monitor the state’s trout populations to see where [stocking] is necessary,” says Hatchery Specialist Troy LeJeune. Stocking maintains populations that would otherwise be unsustainable due to angler harvest or poor water and substrate quality. Native plant and animal communities are taken into consideration before stocking so that the introduced trout do not disrupt any ecosystems. Lanesboro alone currently contributes trout to 67 streams and 101 lakes.
LeJeune says, “This winter has really pushed our [stocking] schedule behind.” The rearing ponds are currently filled to the max with yearling rainbows and browns that are growing bigger every day. He and the rest of the Lanesboro staff are excited to stock when the conditions allow.
Hatchery fish are artificially spawned in fall so that eggs hatch during the winter. The indoor nursery is equipped with red lights, which simulate dawn to encourage increased feeding. The softer lights also reduce stress caused by the hatchery workers’ movements, which are much more visible under normal white lights. The nursery’s capacity is 2.4 million eggs, 85% of which survive to become fry.
Young fish remain in the nursery until they reach 2.25” in length at around four months old, at which point they are referred to as fingerlings. They are then transferred to a covered raceway, protected from predation and sunburn. They are moved to yet another raceway when they grow to be 4” long, where they stay until they are 6-7”. Fish are either stocked as 6-7” fingerlings or moved to rearing ponds to grow to 9-11” yearlings.
Broodstock fish are kept in isolated outdoor raceways, separated by sex and age class. Males of one age class are bred with females of another age class to avoid inbreeding. Maximizing genetic variability in this manner ensures a strong, disease-resistant population.
Since its opening in 1925, Lanesboro’s production has improved drastically, thanks mainly to enhanced disease prevention measures, less stressful handling techniques, and the use of more nutritious feed. The hatchery’s water supply is provided by two artesian springs. Approximately 5,000 gallons of fresh 48˚F water flows into the facility every minute. After being used and cleaned, the water is returned to Duschee Creek.
Before it can be used, however, the radon- and nitrogen-rich water must fall through “splash bars” to remove these toxic elements. While the practice safeguards the health of the fish, the staff’s health suffers for it. LeJeune explained that the splash bars actually send radon into the air that the hatchery workers breathe every day. That isn’t the only health concern at the hatchery.
“It’s just not safe for the staff,” LeJeune says of the mold, poor ventilation, leaky roofs, and rotting doorways in the office building. The nursery, however, is one of the main concerns. Its rusting support beams hint at imminent collapse, and its inefficient insulation means that its internal temperature and the outside temperature are one and the same.
The proposed funding would not only address the infrastructure concerns, but also allow the facility to install a degassing tower. The tower would eliminate nitrogen and radon from the water supply away from the hatchery buildings.
The Minnesota DNR states that without the suggested improvements Lanesboro’s stocking ability will be compromised. LeJeune is hopeful, and shares, “Fry survival is the first thing that we’ll see improve.”
More information on the hatchery and on the public works bill can be found on the Minnesota DNR website.
Originally published in Outdoor News Minnesota