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Return of Oahe: With smelt back, lake's walleyes are rebounding
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Return of Oahe: With smelt back, lake's walleyes are rebounding
[url "mailto:mmcfeely@forumcomm.com"][#0000ff]By Mike McFeely[/#0000ff][/url], The Forum
Published Sunday, June 06, 2004
[url "http://www.in-forum.com/includes/ads/adcount.cfm?id=736"][#0000ff] [/#0000ff][/url]
PIERRE, S.D. – The screen on Tony Dean's sonar showed large, black splotches. One after another, the clouds appeared as Dean moved his boat along the shore of Lake Oahe in search of walleyes.



"Those are baitfish, probably smelt," the outdoors television and radio personality explained. "And that is something I haven't seen on this lake for years."

Rainbow smelt, the prime forage of Oahe's walleyes, are back in the lake in big numbers. It is a sign the 230-mile long Missouri River reservoir that stretches from North Dakota to Pierre is on its way to recovery.

"The smelt have pulled off some pretty good spawns two years in a row. We don't have the numbers yet, but this year looks like far and away the best smelt hatch we've had in years," said South Dakota Game, Fish and Parks Department fisheries biologist Wayne Nelson-Stastny. "This could really kick-start things."

The famed walleye lake needed it. Oahe has been out of whack since 1997 when high water forced the U.S. Army Corps of Engineers to release large volumes of water through Oahe Dam in the spring. The timing could not have been worse. The releases coincided with smelt being in the lower end of the lake in large numbers, so a vast percentage of the lake's smelt were flushed through the dam. [url "javascript:popUp('/articles/full_photo.cfm?id=112128',500,500);"][Image: 0606Outdoors.jpg][/url] It was devastating. Nelson-Stastny said in 1996 Oahe had 44 pounds of smelt per acre. In 1998, there were but 3.3 pounds of smelt per acre.



The result was a predator-prey balance that was terribly awry. In simplest terms, there were way too many hungry walleyes and not nearly enough food for all of them. It didn't take long for Oahe's walleyes – fat and fast-growing through the early to mid-1990s – to start looking more like cigars than footballs.

Prior to 1997, walleyes in Oahe would grow to 19 inches in their first five years, Stastny-Nelson said. In 2000, the growth rate had slowed to less than 14 inches in five years.

"In 1994 and 1995, walleye angling out here was as good as I've ever seen. And that includes the early days of (North Dakota's) Lake Sakakawea. There were big fish and lots of them. You could come out and catch numbers of 4-, 5-, 6-pound fish and bigger," said Dean, a Pierre resident and Oahe regular for more than 30 years. "But with virtually no smelt, the walleyes suffered. You could see it almost immediately."

Biologists at the Game, Fish and Parks Department, Nelson-Stastny said, decided drastic measures needed to be taken if the lake was to rebound quickly. So the department imposed a generous 14-fish walleye limit for Oahe in 2001. That was reduced to a still-generous 10 fish in '02 and '03. Also, anglers could buy a less-expensive fishing license that was good only on Oahe.

The idea, Nelson-Stastny said, was to quickly reduce the walleye population in order to even out the predator-prey balance. That would allow the smelt population to rebound.

The regulation changes were not popular with everybody. In public meetings held prior to the changes, Nelson-Stastny said, locals took the Game, Fish and Park biologists to task.

"People were all over them," Dean said. "But I'm convinced they did the right thing. Their data supported it. If Game and Fish hadn't taken the steps they did, it might have taken 20 years or more for the lake to rebound."

The anglers did come, Nelson-Stastny said, and took many walleyes out of the lake in the first couple of years of liberal limits. The daily limit has returned to six fish this year.

But the higher limits did their job, Nelson-Stastny said. Biologists believe Oahe's walleye and smelt populations are moving quickly toward good health. One sign of that is anglers' catch rates, which are slowing down to more normal levels.

"For years and years prior to 1997, anglers on Oahe would catch one walleye for every three hours on the water," Nelson-Stastny said. "After '97, the catch rate basically tripled to where people were catching one walleye for every hour they were on the water. Now things are slowing down again, which is indicative of a good predator-prey balance. If walleyes have something to eat, people are not going to catch as many of them. You might say it makes the fishing tougher, but what it really does is make fishing more normal."

There are signs that quality fish are returning, too. One day last week, Dean caught a 17½-inch walleye that was too fat to fit in a measuring trough.

"Just like the old days, when these walleyes would have layers of fat on them," Dean said.

Oahe is not completely out of the woods yet, Game, Fish and Parks fisheries biologist Jim Riis said. Drought conditions have water levels in Oahe at record lows and South Dakota, like its neighbor to the north, has been battling the Corps of Engineers to slow water releases out of its reservoirs. The Corps says it needs to release water to support downstream barge traffic.

If water levels in Oahe are too low, the lake will lose much of its cold-water habitat that is crucial to smelt – and game fish – survival.

"Water-level management is still a big part of this," Riis said. "If some changes are made to the way these reservoirs are managed, we can do some good things for fish."

For now, however, the smelt are coming back and the walleyes are getting healthier on Oahe.

Readers can reach Forum reporter Mike McFeely at (701) 241-5580
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