- Associated Press - Sunday, May 17, 2015

MARSEILLES, Ill. (AP) - They aren’t much to look at after they hatch, tiny gray larvae wriggling about inside a glass jar.

But many of these walleye and sauger end up tipping the scales at Illinois River fishing tournaments.

The fish and the anglers can tip their hat to the La Salle Fish Hatchery.

What goes around comes around. Many tournament fish each spring become brood stock for another generation of fry raised at the hatchery.

“We had a bunch of tournaments this year, a lot of opportunities to get our fish in good condition,” said Ed Hansen, hatchery manager.

The life cycle

Each spring the hatchery gathers saugers from the Illinois River and walleyes from the Fox River. At the hatchery, the female’s eggs are artificially fertilized with the male’s milt (sperm) and the eggs are placed in jars of circulating water. As the eggs hatch, the tiny wriggling fry swim up and into tanks.

After putting on a few days of development, they are either stocked into lakes and rivers or into the hatchery’s rearing ponds, where they will spend up to six weeks to reach 2 inches in length.

The crew of five men at the La Salle hatchery raise and release 1 million walleye and 1 million sauger fingerlings (2 inches long) each year. Fry numbers are even larger, such as 12 million to 15 million saugers each year.

These numbers are a function of biology. Half of the fish fry stocked in ponds die.

This mortality rate is far better than in the wild.

“That’s a pretty good expectation to get that many,” Hansen said.

Many fish, walleyes and saugers included, provide no care to their eggs, leaving them at the whim of the environment, predators and other factors. Therefore, these fish evolved a compensation - they lay thousands of eggs.

Fish farming

The La Salle hatchery is a fish farm and millions of saugers and walleyes are its corn and soybeans.

The hatchery also grows a few thousand saugeyes (hybrid crosses of saugers and walleyes), hybrid striped bass, smallmouth bass, largemouth bass, bluegills and redear sunfish.

The hatchery rears as many fish as it can or are needed in lakes and streams, using indoor plumbing and tanks and outdoor ponds. The crop does best at some optimal level - too many reduces productivity, too few wastes resources. As fish grow, the hatchery gives them more space in ponds.

Rick Bushman, assistant hatchery manager, loaded up some clear plastic bags with water and sauger fry, closed them with rubber bands, placed them into Styrofoam coolers, loaded them onto a motorized cart and drove to the ponds.

At shorelines, he opened the bags, half submerged them and splashed pond water inside to acclimate the fry.

He tipped each bag, releasing the tiny fish.

“It will take these guys about 40 days to get an inch-and-a-half,” Bushman said. “Walleye will get there in about 36 days.”

Harvest

The crew uses long seines to harvest stock from ponds. The fingerlings are loaded into tanker trucks, driven to lakes and rivers, and released.

Most walleyes get stocked into the Fox and Kankakee rivers, and most saugers, into the Illinois River.

Saugeyes are a better fit in about five or six lakes.

Next month the hatchery will receive small hybrid striped bass from Arkansas. These will be reared in ponds and distributed to lakes. The next-door La Salle Lake gets its share of bass as well.

“We’ll also get some smallmouth bass and largemouth bass fry and raise those to 4 inches,” Hansen said. This week the bass were delivered from the state’s Jake Wolf hatchery.

Nuke factor

The hatchery, 13 miles south of Marseilles, sits incongruously close to the Exelon nuclear power plant, 2,000 feet to the west. Immediately to the east is La Salle Lake, which supplies and receives water to cool the nuclear reactor. The hatchery draws water from the lake for its 16 ponds.

An intake canal feeds water to the station. Two nets are permanently stretched across the canal to keep out fish, especially shad. The nets require such vigilant upkeep by Exelon that the company keeps a boat moored nearby and has a shed net maintenance building next to the hatchery.

Scary man

The nets and shad attract fish-eating birds like cormorants. Once birds find the shad nets, they occasionally visit the ponds, targeting the hatchery’s crops.

“They wait until the fish get 2-4 inches,” Hansen said.

The hatchery deploys two commercial devices to deter fish-eating birds, Bushman said.

One is the Bird Gard Super Pro, a computerized bird distress call blasted out of speakers.

The other is called “scary man,” Bushman said. This inflatable human figure is set on a timer. About every 20 minutes, a blower inflates the figure, it pops up and a siren goes off.

“I think it works better than anything else,” Bushman said.

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Source: LaSalle News-Tribune, https://bit.ly/1HJZc8L

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Information from: News-Tribune, https://www.newstrib.com

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