Iron River National Fish Hatchery
The West Wing: A New Era for Brook Trout Production
BY CAREY EDWARDS, IRON RIVER NFH
Coaster brook trout production at the Iron River National Fish Hatchery (NFH), where 220,000 fingerlings are produced annually, has been…tricky.
Two glaring difficulties have been water temperature and rearing conditions. The hatchery’s cold spring water isn’t conducive to speedy brook trout growth in late winter and early spring. And the long, deep, rectangular raceways don’t provide the “personal attention” that brook trout need for a sustained healthy growing environment. Trial experiments were run last year to address these issues. The experiments included the use of small circular tanks and the addition of well water from the hatchery’s domestic well. The results were phenomenal! Springs fingerlings left the hatchery healthy and nearly twice their normal size. So…What began as a “What if we tried this?” turned into a “Let’s go full scale!” and thus the West Wing was created.
Construction began with two goals in mind: To provide healthy, larger fish for our partners and to make brook trout rearing easier. So a total of six each small, medium and big circular tanks were installed in the western part of the nursery building. These tanks were fitted with new plumbing that would take advantage of the warmer water from the domestic well, while our spring water is not at the optimal temperature. The tanks are stacked and adjacent to one another to make for easy fish handling and the process goes something like this:
• Hatch small quantities of eggs in specially made jars located in small circular tanks
• Release fry directly into small circular tanks
• Rear fry-fingerlings to the rearing capacity of small tanks
• Release fingerlings directly into medium tanks and grow to rearing capacity
• Inventory and move fish into adjacent large circular tanks and grow until stock out
That’s it! Full scale production is currently underway in the New West Wing and the results to date are noteworthy. Our little fry are close to swim-up and will be feeding soon. Last year’s experiment is still ongoing with a small portion of yearling brook trout brood stock performing well. If the proof of the pudding is in the eating, then Iron River NFH is in for a real treat.