Flooding hurts smelt in lakes Oahe, Sakakawea
BISMARCK, N.D. (AP) -- The bad news: Last summer's high water releases because of Missouri River flooding flushed a lot of smelt out of Lake Oahe in South Dakota and Lake Sakakawea in North Dakota.
Biologists call it entrainment, when fish are flushed through or over man-made structures such as dams.
The good news: The high releases flushed a lot of smelt through the dams and down the river -- and that might be a good thing for anglers.
Dave Fryda, Missouri River system supervisor for the North Dakota Game and Fish Department, said the upshot is the bite for walleyes and pike on the upper reach of Oahe may be better this season because of fewer smelt in the system.
"Fishing should be good this summer in Oahe and the Garrison Reach of the Missouri River because of the suppressed forage issues and the high numbers of walleye and pike," Fryda said. "In addition, both reservoirs have a lot of young walleyes out there, and they likely will be on the bite."
Fryda said going into last season, the smelt populations on Sakakawea and Oahe may have been as good as they were during the heydays in the late 1990s and early 2000s.
"Oahe had possibly its best smelt reproduction in at least a decade," he said.
Hydro-acoustic surveys conducted last July showed exceptional smelt populations in Sakakawea and Oahe, Fryda said. The hydro-acoustic surveys are done during full-moon periods and this year will be done the first week of August, giving biologists a better picture.
"This coming year will be the determining factor," he said.
But record releases from Garrison and Oahe dams resulted in substantial losses of smelt from the reservoirs during the later stages of last summer. That, coupled with higher turbidity or muddier water, contributed to a poor reproductive year for other forage species like crappie and perch on the upper reach of Oahe, Fryda said.
Fewer bait fish in the system should mean hungrier fish and a more aggressive bite, he said.
In terms of comparing the two reservoirs, Fryda said Sakakawea can better withstand a "blip" in the forage fish population than can Oahe.
He said in 2010, fish in Sakakawea showed a strong growth rate for not only forage species but for game species overall.
Shiners, perch and other forage species likely did not take as big of a hit because of the high releases through Garrison Dam as did smelt.
With fewer bait fish, the smaller predator fish like walleye will likely respond by being more aggressive in their feeding patterns. Another positive: Water levels should be high going into the spring. Although the snowpack on the prairie is almost nonexistent, mountain snowpack is about normal, Fryda said.
"Now we are coming into spring knowing we lost quite a few smelt in both reservoirs," Fryda said. "Given high-to-record number of fish predators, smelt spawning conditions this spring will be critical. We have good water levels in both reservoirs, habitat conditions should be good and we still have plenty of adult smelt in both systems. If we can pull off a good smelt spawn, especially in Oahe, we could recover very quickly.".
Boat ramp access will be an issue on the Missouri River. Several ramps may not be open, especially early in the season.
The Game and Fish Department listed Fox Island, Sibley Park and Kneifel Landing, just north of the old Burnt Boat Landing north of Bismarck, as closed.
The Keelboat Landing near the Grant Marsh Bridge, the Sanger Ramp at Cross Ranch State Park and Hoge Island are listed as marginal.
Other than the Fort Yates ramp on the Missouri River, all other ramps are listed as usable.
With the exceptions of Hale Marina and the first low-water ramp at Reunion Bay, all ramps on Lake Sakakawea are listed as usable.
Fryda said while there was a significant loss of smelt up and down the Missouri River system, they tend to bounce back rather quickly and recover under good conditions.
And leading into last year's flooding, both predator and prey populations were in pretty good shape. Both reservoirs have healthy walleye populations and northern pike abundance has never been higher, he said.
"The one positive with the entrainment is it happened under probably the best conditions," he said.