![]() |
Home | Search | Browse | About IPO | Staff | Links |
A Hatchery for all Seasons
Raising mills of fish annually is a complex task.
STORY P.J. PEREA Nestled in the northwest corner of Sand Ridge State Forest 5 miles west of Manito is Jake Wolf Memorial, Fish Hatchery, the largest of four hatcheries managed by DNR's Division Fisheries. The facility, known as Sand Ridge Hatchery until 1985, was renamed in honor of the late Jacob John "Jake" Wolf, former deputy director of the Department pf Consetvation. The hatchery, is a year-round operation that produces an average of 36.5 million fish annually for the lakes, ponds and streams of Illinois. It is located on a large aquifer that provides the facility with a voluminous supply of clean,"54 degrees Fahrenheit groundwater. The chilly groundwater allows the hatchery to raise both cool-water and warm-water fish species, 16 in all, including muskellunge, Skamania steelhead trout, channel catfish, hybrid striped bass, striped bass, northern pike, walleye, brown trout, rainbow trout, coho salmon, chinook salmon, smallmouth bass, largemouth bass, redear sunfish, crappie and bluegill. For those interested in angling, fishery management or the history of Illinois' aquatic resources, a visit to Jake Wolf hatchery will be a fascinating educational experience. The visitor center, located on the upper level, offers a bird's-eye view of the hatchery operations. One, can view a number of exhibits along the halls of the visitor center, including an antique fishing tackle display with hundreds of historical lures, a "Harvesting the River" exhibit that portrays the culture of those living along the Illinois River during the late 1800s and early 1900s and a number of live and mounted fish displays of hatchery fish and trophy Illinois fish.
6 OutdoorIllinois
Because the daily visitor can only view a small slice of operations at Jake Wolf Memorial Fish Hatchery, OutdoorIllinois staff thought it might be interesting to Follow the complex, year-long cycle of raising millions of fish. A glossary of commonly used hatchery terms will help clarify some of the wording used in the story. The hatchery season starts in the late fall and early winter. Migrating ducks and geese fly past the hatchery heralding the cold slowly creeping down from the north. While the pulse of the world slows with the wintry weather, new life enters the hatchery as hundreds of thousands of fertilized trout and salmon eggs arrive from the U.S. Fish and Wildlife Service and the state of Michigan's collection facilities. In November, December, January and February, the salmon and trout eggs hatch. Small, tadpole-shaped fish slowly develop from clumsy fry with bright-yellow yolk sacs into free-swimming miniature versions of their parents known as fingerlings. Microbiologists Steve Shults and Larry Willis closely monitor the health of the trout and salmon for any signs of disease. Although rare, an outbreak has the potential to be disastrous with so many fish concentrated in a relatively small space. Shults explained, "All salmon and trout that are stocked from this facility undergo a health inspection before stocking. This includes examinations for bacteria, parasites, bacterial kidney disease and viruses." When the trout and salmon near stocking size, volunteer groups— Salmon Unlimited from Chicago and students from Wheaton-Edison Middle School—arrive to mark salmon and trout by clipping fins. Salmon Unlimited volunteers have marked salmonids for Lake Michigan since 1985 and plan to continue their work into 2002 and beyond. The Edison Fishing Club is in its third year of fin clipping salmon for the hatchery. Each year's stocking of fish has a specific fin clip to give that year class of trout and salmon a unique marking. Rich Hess, a DNR Lake Michigan fishery biologist, talked about the hard work of the volunteers. "Salmon Unlimited has tagged more than 3.5 million fish for the Department. The members are an incredible resource for fishery managers. The fin-clipping data provides managers and researchers with information about the home range movements, growth, population and age structure of Lake Michigan's salmon and trout. We couldn't do this without their help." Jean Sliwa, co-founder of Salmon Unlimited, has been to every fin clipping event since 1985. Sliwa was almost sidelined with a health problem for the 2001 fin clipping, but didn't let that stop her from coming to help. "I wouldn't miss this for the world!" Sliwa stated. "My late husband helped start this whole thing, and I'll continue to work until I can't do it anymore." Greg Gills and Mark Stankus, teachers at Wheaton-Edison Middle School, organized their third annual hatchery trip for the students of the Edison Fishing Club.
February 2002 7
"The hatchery activity is part of the education and information portion of the fishing club," Gills said. "It really gives the kids an opportunity to be part of the whole process of the fishery." Before the day was done, the class clipped more than 25,000 rainbow trout and chinook salmon. As an added bonus, some of the first muskellunge were arriving at the hatchery for spawning, just in time for students to learn how the state's fiercest aquatic predators start from tiny eggs incubated at the hatchery. Late February and March mark the beginning of the Esocid breeding season, as adult northern pike and muskellunge are netted from Illinois lakes and sent to the hatchery for spawning, and fertilized walleye eggs from Pennsylvania, Colorado and Michigan arrive for the hatching jars. District Fishery Biologist Wayne Herndon spent the first ice-free days of February and March trap netting northern pike and muskellunge from local lakes in order to provide eggs for the next stocking of these toothy predators. The feisty fish arrive in oxygenated horse tanks. Herndon, Fish Culturist Mark Sarti and Hatchery Manager Steve Krueger sort the muskies and collect data about the day's catch. Some of the larger fish require two people to wrestle them out of the tanks and onto a measuring board. Herndon can confirm that a few of the fish are repeat visitors by using a special device known as a PIT tag reader to detect a nearly microscopic metal tag implanted into previously captured fish. The information helps biologists track the growth of individual muskies and allows them to estimate the health and size of a particular lake population. After processing, the fish are moved to holding tanks where they are treated with a reproductive hormone to speed the development of eggs. Once they are ready to spawn, the fish are coaxed into releasing roe and milt. The roe and milt are combined in a stainless steel bowl, and a few Edison Fishing Club students gently stir the mixture with a feather. The cycle of spawning is complete. The fish are then sent back to their home lakes, and the fertilized eggs develop in jars bathed with the continuous flow of cold water. The once amorphous blobs of oil, protein and water now teem with the activity of thousands of developing muskellunge.
8 Outdoor lllinois
In the rack next to the muskie eggs, tiny walleye fry emerge and swim about in their jars, already hungry and ready to grow. Northern pike fry are transferred out of the egg room and placed in a start tank where a mechanical feeder dusts the surface on a regular basis with fish food. "The pike and muskie must be fed continuously or else they'll just start eating each other," Krueger commented. When the warmer weather in April and May coaxes excited gobbles from lonely male turkeys roosting in the trees surrounding the hatchery, it is time for the salmon and trout stocking. The brilliant silver-colored fingerlings, now living in concrete raceways, are guided to a collection pool and transferred to nets. Hatchery trucks are loaded, and after a three-hour drive, the fingerlings arrive at their new residence—the blue-green waters of Lake Michigan. At the same time, millions of walleye fry, now just under 1/4-inch long, are placed into their new homes in state-managed lakes throughout Illinois. Muskie and northern pike are moved to rearing ponds and fed a regular diet of live fathead minnows to condition them to hunt on their own after stocking. Large nets surround the space above and alongside the pond to protect the young Esocids from becoming dinner for fish-eating birds like the cormorants, seagulls, herons and ospreys that frequent the grounds of the hatchery. Occasionally, a device called a bird banger sounds off at the hatchery grounds, causing the hungry birds to scatter, temporarily giving fish a slight reprieve from an almost continual aerial assault.
Largemouth and smallmouth bass brood fish are collected from stock ponds as their spawning season starts toward the end of May and into early June. Unlike many of the cool-water species of fish such as muskellunge and northern pike, bass have relatively complex courting rituals. Raceways are set up with metal nest boxes to allow dominant male bass to establish territories and attract the attention of gravid females. Once the eggs are fertilized, the nest boxes are moved into the hatchery and the eggs processed for incubation. As the smallmouth and largemouth bass fry grow large enough to feed on their own, they are moved to ponds, where they gorge on zoo-plankton for a few weeks. They are then moved from the ponds to tanks in the hatchery, where they are raised on pellets. Young animals flourish both outside and inside the hatchery. Young turkey poults scratch the ground for seeds and insects under the watchful eyes of the mother hen, and does with their young fawns graze quietly along the grassy roadways leading to the hatchery. Inside the hatchery,
February 2002 9
the ponds and raceways are full of schools offish ready for stocking. Summer is a busy time for hatchery personnel as they drive throughout the state supplementing lakes with fingerling striped bass, hybrid striped bass, brown trout, largemouth bass, smallmouth bass, muskellunge, and northern pike. It's also time for channel catfish fry to arrive at the hatchery, move into ponds and be fed on pellets until they are less vulnerable to predatory birds and fish.
Popular panfish species, bluegill and redear sunfish spawn in brood ponds. Dozens of brightly colored male bluegill and redear sunfish tend pie plate-sized nests. The male fish meticulously clean the nest of
As the summer heat subides, the last of the largemouth bass and muskellunge fingerlings leave the hatchery. The ponds are slowly drained, and the young bluegill, redear sunfish and catfish are harvested and transferred to hatchery trucks for pond and lake stocking. Early fall marks the end of the hatchery cycle. The brood fish are returned to their ponds, the raceways stand empty, and the hatchery workers prepare for the arrival of the trout and salmon eggs. Outside, squirrels gather nuts in anticipation of the coming winter, whitetail deer feel the pull of the rutting season, and the first migrating ducks search for a place to feed along the Illinois River. The next time you happen to be in West Central Illinois, plan to visit Sand Ridge State Forest, where you can watch for diverse wildlife and tour the site where millions of fish start their lives before they find a home at a lake, pond or river, possibly near you.
10 OutdoorIllinois |
State Library |