The Current Duluth Area Hatchery was established in 1919.
Why was it established? The facility was established in 1919 as the state’s 6th fish hatchery. It was originally known as the Lake Superior state fish hatchery. In 1975 the French River Cold Water Hatchery (FRCWH) was built nearby to conduct the majority of fish propagation. The Duluth facility now houses Duluth and Lake Superior Area fisheries offices, and the hatchery component of the Duluth facility is used only for rainbow trout egg-take operations. Walleye and white sucker fry production was discontinued in 2007.
What is the general technology used for the hatchery? Technology is very simple for collecting gametes. Compressed air and hand stripping are used to collect eggs and milt from the rainbow trout.
Has the technology been modified since establishment? Recent concerns over disease have resulted in treatment procedures to disinfect eggs.
In general, fish management tools fall into one of four categories:
Lake and stream surveys along with research studies provide the information used to select appropriate management tools.
NORTH SHORE STEELHEAD AND KAMLOOPS MANAGEMENT
The steelhead and Kamloops strains of rainbow trout provide a unique opportunity for those fishing the North Shore of Minnesota. Anglers spend anywhere from approximately 20,000 to 48,000 hours each spring fishing for rainbow trout, catching an estimated 1,584 to 8,492 rainbow trout. Harvest is allowed on Kamloops, while steelhead are catch-and-release only.
Hatchery production is an integral part of Lake Superior rainbow trout management. Steelhead stocking has increased the numbers of steelhead returning to the Knife River, and annual production of 92,500 Kamloops provides a harvest component to the Lake Superior rainbow trout fishery.
There are a number of reasons for stocking, including:
Steelhead stocking is meant to supplement the naturally reproducing populations. The goal of Kamloops stocking is to maintain a put-grow-take fishery for anglers who enjoy harvesting rainbow trout.
While stocking is an important fisheries management tool, it is expensive and not the solution to all fisheries problems. In some situations stocking can even be detrimental to existing populations. Often times stocking merely serves as a “band-aid” approach to a problem and does not address the actual cause of the problem. Changes to a stream’s watershed and riparian zone can change stream flow, reduce water quality, and damage habitat, resulting in unsuitable conditions for many of our prized trout species. The best way to ensure a resource will be present for future generations is by being a responsible steward and protecting the habitat we have and restoring habitat we have degraded.
STEELHEAD AND KAMLOOPS EGG COLLECTION
When spring water temperatures rise into the 40s, generally in April and early May, both the steelhead and Kamloops strains of rainbow trout enter Lake Superior tributaries to spawn. At the French River, a trap at the river mouth captures these fish as they swim upstream. Fish are brought into the spawning facility next to the river, spawned, and released. The fertilized eggs are treated to prevent disease and are transported to the Spire Valley hatchery in Remer, MN. Historically the eggs were hatched on-site at the FRCWH, but disease concerns and the high costs associated with running the FRCWH rearing facilities year-round prompted the change in rearing location.
The eggs hatch into fry after several weeks. Steelhead fry (~1 inch long) are loaded onto trucks at Spire Valley and delivered to North Shore streams. Young steelhead that spend two years in the stream imprint of the scent of the river during a process of physiological change called smoltification. These smolts emigrate to Lake Superior to grow into adults. After two or three more years they return to their home river to spawn.
Kamloops gametes are taken at the French River each spring and because of disease concerns and the high costs associated with running the FRCWH rearing facilities year-round they are transferred to the Spire Valley Hatchery. After the Kamloops eggs hatch, the young fish are raised in the Spire Valley Hatchery until the following spring when they are brought back to the FRCWH to imprint and grow larger before being stocked into the McQuade Harbor and the French and Lester Rivers. Because Kamloops are raised in a hatchery environment they grow large enough to reach smoltification size in only one year. Like steelhead, Kamloops spend several years in Lake Superior before returning to spawn. Unlike salmon, rainbow trout do not die after spawning and can reproduce several times over their lifetime.
What types of research help with management decisions for this facility? Hatching rates and survival to fry and yearling sizes allows us to determine how many pairs of fish need to be spawned to meet the established quotas. There is no need to take extra eggs if the space isn’t available to raise them. Survival of stocked fish is monitored annually to determine how much the stocked fish are contributing to the fishery.
What other factors are involved with management decisions involving this facility? Lake Superior is home to many exotic species that the MN DNR does not want to spread inland, especially Viral Hemorrhagic Septicemia (VHS). Concern over aquatic invasive species has resulted in development of a plan to maintain the steelhead and Kamloops stocking programs while minimizing the risk of spreading VHS. Operational costs and the desires of anglers also play an important role in the management decision.
What types of research or other science activities occur along with the activities in this facility? Scientific study is essential for evaluating hatchery programs. Evaluation of steelhead stocking life-stages has shown that stocking steelhead fry is the most cost-effective stocking strategy to increase the number of steelhead for North Shore anglers. Simply stocking more and more fry doesn’t guarantee more adult steelhead however. Research has shown that <1% of steelhead fry that emigrate before age-2 return as adults, whereas 11% of age-2 emigrants return as adults. The number of age-2 emigrants a stream can produce depends on many factors, including weather conditions, food supply, and availability of habitat.
Return rates of Kamloops to the French River trap and to anglers has been monitored for years and will continue so that we can determine if the changes in rearing facilities are worth the cost savings. Size at stocking, and time of year Kamloops are stocked are important considerations.
How does the data collected and/or research conducted at this facility inform/affect fisheries managers and fisheries habitats? The data collected on the adults captured for spawning allows fisheries staff to determine the status of the steelhead and Kamloops populations in Lake Superior, and to evaluate changes in these respective programs.
This facility has an outdoor trail with interpretive signs illustrating the egg take process on the French River.