DES MOINES - The Iowa DNR wrapped up its initial fish stocking for the spring, releasing 112 million walleye fry into Iowa lakes, 263,000 northern pike into lakes and rivers, and about 2,500 muskies into four lakes. The muskies were spawned in 2010.
"It took a little longer for the eggs to hatch this spring because the water temperature in the hatcheries was cooler than normal from all the cold fronts that moved through," said Mike Mason, supervisor for fish hatcheries with the Iowa DNR.
Mason said hatcheries will be stocking 2-inch walleyes fingerlings in June, then 5 to 6-inch fingerlings this fall, all kept at the hatcheries and rearing ponds from the same fry hatch that was stocked in May.
"These fingerling walleyes will have an increasingly better chance for survival the larger they grow," Mason said. "Our fry stockings have about a one-tenth of one percent survival rate and when we do see higher fry survival, we see a really strong year class which anglers will see in their catch rates."
Walleyes are not the only species spawned and stocked in the spring. Northern pike captured on the Mississippi River are spawned in late March. A portion of the hatched pike will be part of a study by the fisheries bureau.
At the Fairport fish hatchery, 7,100 northern pike grown to fingerling size were freeze branded before being stocked in Bussey Lake, in the Mississippi River, that will be the first step in a multi-year effort to recapture fish in the future and document growth of known age fish to better manage northern pike on the Mississippi River.
"We are always looking at ways that we can improve hatch rates, survival, growth and quality of fish that we produce," Mason said. "These pike will be studied for years and hopefully provide quality data that will benefit future stockings and river management."