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Iowa Walleye: Widespread Gains for Anglers as Researchers Build Fishing "Field of Dreams"
DES MOINES - No one who has ever seen Field of Dreams can forget the signature line from that motion picture: "Build it and they will come."
What if the scenario of a mythic Iowa cornfield was changed just a bit: no ball diamonds, but fishing lakes amidst fields of Iowa corn? And what if the fabled legend to emerge from another era was a fish, one that's particular about its need for clear, clean water?
The fish is the walleye. The State is Iowa. And the tale is completely true.
Walleye are not the easiest fish to raise in a hatchery. In fact, they present some very unique and difficult challenges to hatchery managers. But because the walleye is so popular with anglers, many states invest considerable time and money to assure their success.
Iowa's approach to improving its walleye fishery has always been guided by two goals: fostering better fishing, and stocking a healthy, hatchery raised fish that survives well after stocking in lakes and streams.
The Iowa DNR began a comprehensive effort to improve its walleye fisheries more than 25 years ago. According to Marion Conover, Fisheries bureau chief, surveys showed that walleye were among the most sought-after sport fish by anglers. Yet, the species enjoyed only limited natural reproduction in much of the state.
"Many Iowans may not realize the science and research behind the great walleye fishing we now have in Iowa," said Conover. "It's a fascinating process of understanding the biology of fish survival and growth, and our researchers have dedicated many hours of time to building a successful walleye fishery our anglers can enjoy for many years to come."
While DNR researchers have been able to demonstrate that stocking walleye fry - newly hatched fish -- can survive and grow to an angler-acceptable size, many lake and stream environments make survival of these tiny fish very difficult. In addition, research has shown that stocking larger walleye fingerlings in lakes produces better survival rates and thus better harvests for anglers.
Getting walleye fingerlings to an advanced stocking size, however, required innovation and a willingness to explore new techniques. One method pioneered by Iowa involves transferring walleye fry from hatchery ponds to tanks in dark rooms, where they are trained to accept a specially formulated high-protein pellet feed.
"The darkened room reduces stress on the young fish, which in turn increases acceptance of the new diet and growth of the small fish," said Conover.
As a result, Iowa enjoys unusually high survival rates from the fry stage to larger fingerling available for stocking. This past year the survival rate was 85 percent, an almost unheard of achievement when compared to other methods.
Iowa's work has focused on refining its efforts. Along the way, the DNR has been able to show, quite compellingly, that improved water quality not only yields better angling success, but contributes dramatically to increased outdoor recreational use as well.
The proof? One Iowa state park, Lake Ahquabi in Warren County, saw its visitation figures grow tenfold, from 60,000 visits per year to 600,000, due to its dramatically improved water quality and recreational fishing.
Other Iowa lakes benefiting from the walleye research program include Big Creek, Rathbun Reservoir, Sugema Lake, West Okoboji, DeSoto Bend, Manawa, Storm Lake, Black Hawk Lake, Brushy Creek, Lake Icaria, Little River Lake, Three Mile, Twelve Mile and Clear Lake, all of which are now prime walleye fishing venues because of stocking large walleye from state hatcheries.
The walleye work carried out in Iowa was made possible by the sales of Iowa fishing licenses and by the federal Sport Fish Restoration (SFR) program. SFR dollars are those funds derived from special excise tax monies collected on fishing tackle and motorboat fuel. These are the funds provided by anglers and boaters each time they purchase the equipment and fuel essential to their outdoor pursuits.
"Every time an Iowa angler buys a license or purchases fishing gear or boat fuel, they are making a real difference to Iowa's lakes and fish," said Conover.
The DNR's groundbreaking work will have valuable applications well beyond the Hawkeye State, as other states learn from Iowa's example, proving once again that "if you build it they will come."
For more information, contact Mike Mason, Supervisor of Hatcheries, (515) 281-6072 or Andy Moore, Rathbun Fish Hatchery/Research Supervisor (641) 647-2406
Iowa Walleye: Widespread Gains for Anglers as Researchers Build Fishing "Field of Dreams"
DES MOINES - No one who has ever seen Field of Dreams can forget the signature line from that motion picture: "Build it and they will come."
What if the scenario of a mythic Iowa cornfield was changed just a bit: no ball diamonds, but fishing lakes amidst fields of Iowa corn? And what if the fabled legend to emerge from another era was a fish, one that's particular about its need for clear, clean water?
The fish is the walleye. The State is Iowa. And the tale is completely true.
Walleye are not the easiest fish to raise in a hatchery. In fact, they present some very unique and difficult challenges to hatchery managers. But because the walleye is so popular with anglers, many states invest considerable time and money to assure their success.
Iowa's approach to improving its walleye fishery has always been guided by two goals: fostering better fishing, and stocking a healthy, hatchery raised fish that survives well after stocking in lakes and streams.
The Iowa DNR began a comprehensive effort to improve its walleye fisheries more than 25 years ago. According to Marion Conover, Fisheries bureau chief, surveys showed that walleye were among the most sought-after sport fish by anglers. Yet, the species enjoyed only limited natural reproduction in much of the state.
"Many Iowans may not realize the science and research behind the great walleye fishing we now have in Iowa," said Conover. "It's a fascinating process of understanding the biology of fish survival and growth, and our researchers have dedicated many hours of time to building a successful walleye fishery our anglers can enjoy for many years to come."
While DNR researchers have been able to demonstrate that stocking walleye fry - newly hatched fish -- can survive and grow to an angler-acceptable size, many lake and stream environments make survival of these tiny fish very difficult. In addition, research has shown that stocking larger walleye fingerlings in lakes produces better survival rates and thus better harvests for anglers.
Getting walleye fingerlings to an advanced stocking size, however, required innovation and a willingness to explore new techniques. One method pioneered by Iowa involves transferring walleye fry from hatchery ponds to tanks in dark rooms, where they are trained to accept a specially formulated high-protein pellet feed.
"The darkened room reduces stress on the young fish, which in turn increases acceptance of the new diet and growth of the small fish," said Conover.
As a result, Iowa enjoys unusually high survival rates from the fry stage to larger fingerling available for stocking. This past year the survival rate was 85 percent, an almost unheard of achievement when compared to other methods.
Iowa's work has focused on refining its efforts. Along the way, the DNR has been able to show, quite compellingly, that improved water quality not only yields better angling success, but contributes dramatically to increased outdoor recreational use as well.
The proof? One Iowa state park, Lake Ahquabi in Warren County, saw its visitation figures grow tenfold, from 60,000 visits per year to 600,000, due to its dramatically improved water quality and recreational fishing.
Other Iowa lakes benefiting from the walleye research program include Big Creek, Rathbun Reservoir, Sugema Lake, West Okoboji, DeSoto Bend, Manawa, Storm Lake, Black Hawk Lake, Brushy Creek, Lake Icaria, Little River Lake, Three Mile, Twelve Mile and Clear Lake, all of which are now prime walleye fishing venues because of stocking large walleye from state hatcheries.
The walleye work carried out in Iowa was made possible by the sales of Iowa fishing licenses and by the federal Sport Fish Restoration (SFR) program. SFR dollars are those funds derived from special excise tax monies collected on fishing tackle and motorboat fuel. These are the funds provided by anglers and boaters each time they purchase the equipment and fuel essential to their outdoor pursuits.
"Every time an Iowa angler buys a license or purchases fishing gear or boat fuel, they are making a real difference to Iowa's lakes and fish," said Conover.
The DNR's groundbreaking work will have valuable applications well beyond the Hawkeye State, as other states learn from Iowa's example, proving once again that "if you build it they will come."
For more information, contact Mike Mason, Supervisor of Hatcheries, (515) 281-6072 or Andy Moore, Rathbun Fish Hatchery/Research Supervisor (641) 647-2406
