New cool-water complex boosts walleye and muskellunge production

A new cool-water fish production facility at Thompson State Fish Hatchery, which will support walleye and muskellunge stocking, is in the final stages of construction, and fish are already being reared there.

Walleye eggs were collected from Little Bay de Noc early this spring and were incubated and hatched in the new state-of-the-art hatchery. Muskellunge will be transferred from Wolf Lake Hatchery in Mattawan during August each year and reared at Thompson State Fish Hatchery in Manistique until November, when they will be stocked depending on need across the state.

“For nearly 150 years, the Fisheries Division has reared fish in facilities designed specifically for trout and salmon,” said DNR Fisheries Division Chief Jim Dexter. “This is our first completely separate cool-water facility, which is important for managing the risk of disease and improving our capability to deliver cool-water fish such as walleye and muskellunge.”

The new facility includes a hatchery building with a biosecure room for receiving and disinfecting eggs, and an egg incubation and hatching room with several tanks for receiving hatched walleye fry. The incubation water, supplied by two new wells, can be heated or chilled to manage the timing of fry hatching. The electrical infrastructure is backed up with a new generator that starts automatically if primary power is lost.

A new pond complex, including two 1-acre lined ponds and four half-acre lined ponds in addition to a solar pond that allows cold water to warm before reaching the rearing ponds, will give fish rearing a boost.

“With our new pond complex, we should be able to produce up to 250,000 spring walleye fingerlings and 18,000 fall muskellunge fingerlings each year,” said Ed Eisch, DNR fish production program manager. “This new facility and pond complex will help us continue to provide world-class fishing opportunities throughout the state.”

Each of the rearing ponds has aeration equipment to maintain oxygen levels and an internal harvest kettle – which holds the fish as the pond drains and makes it easy to collect them – that will be used when the fish are ready to be stocked.

An external harvest kettle is connected to all six rearing ponds. With the facility only 1 mile from Lake Michigan, fish-eating birds like cormorants, arctic terns and mergansers were a concern during design. To protect the fish, each pond is entirely enclosed by predator exclusion netting. This facility will serve Michigan’s anglers well into the future.

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