Hatching plans and walleyes: Students volunteer with DNR during spawn
It was a rainy, windy and generally miserable morning on Monday, but the walleye were on their way to spawn – and there was work to do.
Biologists and staff from the Minnesota Department of Natural Resources fisheries office in Fergus Falls put on their waders and waterproof gear, and jumped into 40-degree water. They sorted fish from the trap – walleyes from the others, males from females, “ripe” from “green” – and plopped them into the appropriate bucket.
All fish other than walleyes were released right away. “Ripe” walleyes were stripped of their eggs or milt, then released back into the river. Those that were still “green” went into a holding crib to be checked the next day.
Two students from Perham High School, Austen Schultz and Austin Erickson, stood by and helped the process go faster by moving sorted fish from bin to bin.
As the fish were stripped, another biologist stirred the mix with a feather to keep the eggs from clumping or breaking. Eggs were then rinsed, carried back to the hatchery, checked over for contaminants and put into incubator batteries.
The egg collection will continue until the hatchery meets its quota. This year, it’s about 500 quarts.
Three weeks later, the eggs will start to hatch and most of the walleye fry will be taken to lakes in Otter Tail County, Ortonville and Glenwood as part of the state’s stocking program. Some others are kept in rearing ponds to be stocked later, as fingerlings.
In all, the DNR staff spends about five weeks working with the walleye spawn and hatch process.
The Walker Lake Hatchery was established in 1974. Since that time, not much has changed in the way walleye are trapped, sorted or stripped. Mesh screen is still used to rinse the eggs. Inside the hatchery, gravity, rather than a pump, is used to distribute and circulate water from the river.
One key difference, fisheries technician Mike Nelson said, is a complex filtration system that is now in place to protect the hatchery from aquatic invasive species, viruses or fungi.
If the surrounding lakes and river were to become infested, Nelson said, the filters and ultraviolet chambers are designed to keep the system isolated, so they could continue to stock their fry whenever needed.
Stocking plays a comparatively small role in maintaining the walleye population throughout Minnesota, according to the DNR. Of the 3.5 million walleye caught by anglers each year, the DNR estimates 4 percent (140,000) of those fish were originally stocked.
Sometimes, Nelson said, a lake just doesn’t support a population capable of replenishing itself.
In addition to supporting a healthy population for fishing, stocking can also be used to help restore populations in lakes that have been “rehabilitated” or suffered severe winterkill.
“It’s been good for them,” Nelson said of student volunteers from past years. “We’ve had quite a few over the years who might want to get into the field.”
The partnership between the hatchery and Perham High School began about seven years ago through the work of science teacher Rebecca Rennicke, Nelson said. Shawn Stafki took over as coordinator this winter.