The Garrison Dam Tailrace on the Missouri River has been the hottest fishing hole in North Dakota since the boat ramp reopened Aug. 18 after a summer of flooding, but there's a dark side to what's happening below the tailrace that concerns Game and Fish Department officials.
Fish by the hundreds -- smelt and ciscoes, mainly, but also species such as salmon and paddlefish -- have died after being washed through the dam in the high water. Greg Power, fisheries chief for the North Dakota Game and Fish Department in Bismarck, said dead ciscoes -- or tullibees, as they also are called -- washed up onshore as far downstream as south of Bismarck.
"Lots of them -- littering the shoreline," Power said.
Known in fisheries terms as "entrainment," the die-offs are troubling because smelt and, to a lesser extent, ciscoes, are primary forage for walleyes, salmon and other species in Lake Sakakawea and throughout the Missouri River system.
Power said smelt populations have been on the rebound as water levels along the Missouri and its reservoirs rebounded after years of low water. This summer's flooding, which forced water managers to open the gates of the Garrison Dam Spillway for the first time in its 58-year history, appears to have been too much of a good thing, though.
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"The smelt issue has just come up big time," Power said.
Power says he wasn't surprised to see a few paddlefish lost to the dam when the gates were open because they're a warm-water species that generally stay close to the surface.
Now that the gates again are closed, though, Power said dead paddlefish still are showing up downstream from the dam.
"We continue to see too many paddlefish showing up going through the power house and flood tunnel, and that's 180-200 feet deep," Power said. Fisheries personnel in Riverdale, N.D., are monitoring the situation, he said, but there's not much they can do about it.
Power says it's difficult to say how many paddlefish and other species have died from washing through the spillway or intake structure. He said the department eventually hopes to determine a reasonable estimate on paddlefish mortality "instead of lots or too many."
"It's ongoing, and we're not going to be able to quantify it" yet, he said. "We'll know more maybe in a month or month and a half."
The smelt die-off below the dam is especially obvious right now, said Jeremy Foss of Minot, whose wife, Alecia, caught a 15-pound, 4-ounce walleye last Saturday night below the tailrace.
The walleye was the largest to be reported in North Dakota since the state record 15-pound, 12-ounce fish was caught in Wood Lake in Benson County in 1959.
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Berg's big fish likely was fattening up on the smelt smorgasbord.
"It's unbelievable," Jeremy Berg said. "It just reeks like dead fish because there are so many smelt floating around."
Power said species such as walleyes and saugers are less susceptible to being washed through the dam because they tend to hunker down when flows are high. No doubt, he said, they're living well in the tailrace with the easy pickings.
"Three weeks ago, when they opened up the ramp, the fishing was probably as close to 'jumping in the boat' as you could get," Power said. "Walleye and sauger fishing was unbelievably easy, and nice fish, too. That's why you had 170 boat trailers at one ramp."
Walleye fishing since has slowed, Power said, but the salmon fishing below the tailrace has picked up the past 10 days.
"They're starting to go out and troll with downriggers in the chutes," he said. "The chutes are only 20, maybe 30 feet at the most."
Power said he's hoping the smelt die-off doesn't reach the scale of what happened on Lake Oahe in 1997, when the Missouri River reservoir lost an estimated 90 percent to 95 percent of its smelt population during a high-water event.
The intake structure at Garrison is different than Oahe, Power said, and the smelt in Oahe were swimming right in the intake zone when they got swept through the dam.
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"That was really an unfortunate event, so that's been one of our No. 1 concerns -- that we're going to have a repeat of that situation this year" at Garrison, Power said. "The time is right now if it's going to happen. If you lose a lot of forage, it really sets us back again."
He said the department isn't planning any special studies into the die-offs.
"There's not much you can do about it anyway, if it's a one-in-500-year event," Power said of the summer flooding. "You might learn something, but it's not like we can change the releases."
Dokken reports on outdoors. Reach him at (701) 780-1148; (800) 477-6572, ext. 148; or send e-mail to bdokken@gfherald.com .
