Their day usually starts about 8 a.m. and lasts until 3 a.m. the following morning.
Then it's bedtime until the 7:30 a.m. wake-up call to start all over.
Just a typical day for fisheries crews from the Iowa Department of Natural Resources as they gear up for the annual spring walleye stocking.
Netting started last Friday on Storm Lake, and the fish numbers so far have been "tremendous," foreshadowing a potential banner year for local anglers. The net operation should continue for another two or three days, according to DNR Fisheries Biologist Lannie Miller. Crews are collecting walleyes for the eggs and semen to be used in the state stocking program.
Crews also have been out on Clear Lake and Lake Rathbun, and should be starting on the Iowa Great Lakes.
The walleye produced from the eggs and semen collected in Storm Lake will help provide fish for the entire state. It's needed because there is a lack in natural reproduction by walleyes in Iowa lakes and streams.
"I can say with almost certainty that if an angler catches a walleye in Iowa, more than likely that fish came from one of our hatcheries," said Marion Conover, chief of the DNR's fisheries bureau. "We do have some instances of natural reproduction in our natural lakes, but the overwhelming majority of walleyes came from eggs from the fish we collected in the gill nets."
Fish Roundup / See Back
Workers set the gill nets in the evening and collect fish twice during the night. The fish are separated by sexes in holding tanks at the fish station. The females are checked for ripeness, meaning if they are ready to release their eggs or if they are "green." The green females will go to a different tank until they are ready to release their eggs.
During the day, the workers remove semen and eggs. It takes roughly two males to fertilize the eggs from one female.
The Storm Lake effort works better now that the DNR biologists and technicians can work in the comfort of their own permanent fish station. In the past, the DNR has utilized the shop area at Casino Beach Marina. One of the problems there was that the DNR had to set up all of its equipment, and then tear it down again once the season was over.
"It was an awful lot of work for us, besides getting fish and stripping them," Miller said. "The beauty of the new facility is that before we couldn't hold fish very long. Now we can which means more eggs."
Another advantage to the facility is that fish no longer have to be held in net cages at the marina; instead, they are located in holding tanks in the building.
Across the state, the goal is to collect enough fish to fill 1,200 quart jars with eggs. That's about 200 million eggs. The survival rate is about 70 percent, or about 150 million walleye fry.
The newly hatched walleye fry will go into rivers and lakes across the state. Some will go to the hatcheries at Rathbun and Spirit Lake where they are grown to 2 inches before being stocked. These 2-inch fingerlings have a better survival rate then the fry. And still other fish will be kept at the hatcheries and grown to 8 inches before being released in lakes and streams. They have the best chance to survive, but also cost more to produce.
The process, which happens about the same time each spring, can be cold and tiring. The water temperature is usually in the low 40s and the weather changes dramatically from day to day. But if the DNR did not collect these walleyes, anglers would notice a dramatic decline in walleye fishing all across the state.
Fluctuating water temperatures in Storm Lake has slowed the operation down somewhat this year. "The water temperature was 46 degrees when we started and then it dropped to 41 degrees," Miller said. "That harms us because the females don't ripen up as fast."
The operation also allows the DNR to survey the existing fish stock. And it's a good crop this year.
"Our biologists and technicians here cover half of the state and they say they've never seen fish in such good shape," Miller said. "They're in excellent condition, with 18, 19, 20-inch fish."
As temperatures warm up, so will the fishing.
"People will see tremendous fishing here," Miller said. "There's a lot of walleye swimming in the lake this year."
Sidebar: DNR begins stocking pike fry
The DNR began stocking more than 1.1 million northern pike fry on Monday and are continuing the stockings this week. Pike fry will be stocked in the Winnebago River, the Shell Rock River, the Wapsipinison River and Saylorville Lake. Any extra fry will be stocked in the Mississippi River.
About 300,000 pike fry will go to Spirit Lake and grown to 3 inches before being stocked in rivers and lakes across the state.