Iowa’s current State of Emergency to help stop the spread of COVID-19 changed how the Iowa Department of Natural Resources (DNR) collected walleye this spring to spawn at Rathbun and Spirit Lake fish hatcheries.
“Our employees are our most valuable resource,” said Jay Rudacille, DNR Warm and Coolwater Fish Culture supervisor. “Because of the coronavirus pandemic, we only used local staff to collect walleye broodstock and shortened the netting season to reduce staff interactions and maximize the safety of every employee.
“We adjusted our goals to limit the time crews were out collecting adult walleyes. Even with reduced walleye collection goals, we will still meet requests for our highest priority needs and locations,” said Rudacille.
Walleye broodstock collection at Rathbun Lake wrapped up after five nights of netting. It usually takes 8-10 nights of netting in a normal year. The goal at Rathbun Lake was to collect 170 females and three crews exceeded this goal by 26 percent.
Two crews at Spirit Lake netted three nights and surpassed the 650 egg-filled females quota by 12 percent. Their netting efforts were supplemented by electrofishing in East Okoboji Lake and the spillway connecting East Okoboji and Spirit Lakes.
Two crews netted a total of five nights at Black Hawk Lake, providing nearly 143 quarts of eggs, which exceeded their goal by 43 percent.
Staff at Rathbun Fish Hatchery are incubating 544 quarts of walleye eggs, including 143 quarts from Black Hawk Lake. At Spirit Lake Fish Hatchery, 617 walleye females were spawned, producing almost 540 quarts of eggs. A total of 84 million walleye hatchlings will be produced from the 2020 egg collection.
Iowa is one of the top producers of walleye fry (newly hatched fish) in the United States, second only to Minnesota. Because of reduced production goals, the DNR will only release 82.9 million walleye fry this spring instead of the original goal of 142.6 million.
“There was nothing normal about this year, but I’m very proud of what our netting crews and hatchery personnel were able to accomplish,” Rudacille said.
While the majority of walleyes are stocked as fry, some are cultured in Iowa DNR hatcheries and stocked at different sizes. More than1.1 million two-inch walleyes are expected to be stocked into lakes, rivers, and streams across the state this summer. Larger 6- 9-inch fingerlings (more than 310,000) will be stocked in lakes later this fall.
With little natural reproduction, Iowa’s walleye populations rely heavily upon stockings. Walleyes are stocked throughout Iowa into natural lakes, interior rivers, flood control reservoirs and selected larger man-made lakes.