On Friday, April 12, the Minnesota Department of Natural Resources began their walleye egg-stripping operations at the Cutfoot Sioux site.
Walleye stocking creates walleye catch opportunities in places that do not have good natural reproduction, but the vast majority of the walleye caught in Minnesota are naturally reproducing fish because of good habitat and water quality.
The Grand Rapids Hatchery was initially located near the spawn take sit at Little Cut Foot Sioux Lake but is now at its current location and is more sophisticated than the wood structure that was built in the 1920s. The current hatchery was established in 1998.
The spawning run at Cut Foot Sioux is the largest spawning run in the state and is the primary producer of Mississippi Strain walleye. The run has produced on average over 1,300 quarts of eggs and over 90 million walleye fry annually since 1990.
At the run, temporary docks are put in every year and then the docks are taken back out when they are finished. A net is set up across the waters that funnels the fish into the trap. The fish are checked every day to see if they’re ripe and ready to be stripped (expressing the eggs). Any excess fish are let out of the net.
Doyle Haas, Grand Rapids Area Assistant Fisheries Supervisor, said they only hold the females up to three days and there are three cribs to hold them. Because they deal with so many fish and because they’re not all ripe on the same day, the three cribs are utilized to section off a large chuck of the fish. They are all sorted by hand. When a fish is ready to be stripped, it goes into a wash tub and is then taken to the stripping table.
Doyle said they have changed methods from a dry method to a wet method and have seen more success. The fish and eggs are put into pans that are swirled around and mixed with mud to increase likelihood of fertilization. The eggs are then taken to the coolers at the site for two hours because of their sensitivities until a hard shell forms.
Eggs are transported daily back to the hatchery at the Grand Rapids location where they are put into jars. After they hatch, they then are stocked as fry or moved into large rearing ponds to grow into fingerlings for fall stocking.
In the hatchery, the rate of success is variable but Doyle said that during the dry method they had about a 50-60% chance of success and now after they switched to the wet method, it went up to 70-80%.
Walleye begin spawning in April as water temperatures approach 45 degrees. Workers collect and combine the eggs and milt from walleye spawning at the Cutfoot station. Spawning usually lasts one to three weeks. The fertilized eggs are transported to the hatchery and hatch in about three weeks.
Doyle said, “We want to put them somewhere where they have a good chance of survival… big, deep lakes generally aren’t great… shallow and warm lakes have more food, plankton, to eat.”
The Grand Rapids site coordinates with other hatcheries in the region like Tower, Pike River, Pine River, Park Rapids, Bemidji, and Brainerd. The GR location also partners with the Leech Lake Band.
The number of eggs taken from this Cut Foot does not harm the home water’s fish population. The DNR returns more hatched fry to the host site than what would have hatched naturally in nature.
Minnesota has more walleye, walleye lakes, and walleye anglers than any other state. And while the best way to maintain walleye numbers is to protect critical habitats, stocking is another management tool used.
The DNR conducts lake surveys and assessments to determine where walleye stocking may benefit a lake and where it is ineffective. These evaluations help them determine appropriate stocking levels and frequencies.
Most of the eggs collected at Cutfoot are sent to other hatcheries for hatching and rearing. The eggs will go all over the state. Many eggs go to southern and western Minnesota for use in walleye fingerling ponds to produce fall fingerlings.
Most Popular
Comments / 0