Low water levels threaten long-term health of Lake Sakakawea's fishery

GARRISON, N.D. -- As Brig. Gen. David Fastabend stood before about 250 people in the Garrison City Auditorium on a recent evening, explaining the U.S. Army Corps of Engineers' position on water levels along the Missouri River system, a man stood near the back of the room holding a sign.

"Save Lake Sak," it read.

It spoke for every person in the building who showed up to hear Fastabend speak and to speak to him. It spoke for fishermen, resort owners, other business people and for North Dakota itself, which was represented at the meeting by Gov. John Hoeven.

Save Lake Sakakawea, the massive Missouri River reservoir that is state's most popular fishing destination and is estimated to generate $23 million annually in angling-related revenue during high-water years.

Fastabend, who heads the Corps division charged with managing the Missouri and its reservoirs, promised the Corps would provide access to the lake, even as water levels dip to drastically low levels this summer. The ongoing drought and releases from Garrison Dam to support downstream barge traffic are expected to drop Sakakawea to somewhere near a record low 1,815 feet above sea level, which occurred in 1991. Fastabend said it could go significantly lower, depending on the severity of the drought.

As for saving Sakakawea's fishery -- which includes healthy populations of walleyes and salmon that depend on a forage base of rainbow smelt -- Fastabend gave no assurances.

"I cannot promise you a successful outcome," he said.

Those are ominous words for North Dakota and other upper basin states like South Dakota and Montana that have established successful cold-water fisheries in Missouri River reservoirs.

While controversy continues to swirl about the Corps' management of the river, the political maneuverings involving barge traffic in Missouri and the 14-year battle over revising the Master Manual for management of the river, those interested in Lake Sakakawea have a much more immediate concern: Low water this summer could do severe long-term damage to the fishery.

"Nothing is assured," said Greg Power, a fisheries biologist with the North Dakota Game and Fish Department. "But the likelihood increases as the lake falls below 1,825 feet."

The Game and Fish Department supports lake levels between 1,837.5 feet and 1,846 feet and said Sakakawea's fishery begins to show stress when summer elevations drop below 1,830 feet. Currently, the lake's level is about 1,820 feet.

It's all about the smelt, a small silvery baitfish that inhabits Sakakawea's depths by the tens of millions and is gobbled up by predators like walleyes, salmon and northern pike.

When the smelt population is healthy, fish populations as a whole are healthy. When the smelt population drops, the numbers of game fish and their health decline.

"It's a domino effect," Power said.

Game and Fish studies show that almost 96 percent of smelt eggs are deposited in water of one foot or less. That means even minor declines in lake elevation during the spring can greatly reduce smelt reproduction when eggs are left high and dry.

"That leads to either weak or missing smelt year classes that ultimately affect the Lake Sakakawea fishery for several years," said Terry Steinwand, chief of the fisheries division for the Game and Fish Department.

Of equal concern is declining lake levels in the summer. If elevations are below 1,825 feet, Sakakawea's cold-water habitat -- the volume of water in the lake at 59 degrees Fahrenheit or colder and containing five parts per million of oxygen, where smelt thrive -- is greatly reduced. That stresses smelt, Steinwand said, resulting in poor growth and condition.

When lower oxygen levels and higher water temperatures persist for extended periods, it can lead to a widespread smelt die-off. That's what occurred in September 1990, when Sakakawea was at an elevation of 1,821 feet.

"The list of problems created by chronically low water levels is endless," Steinwand said. "Simply throwing money at access is not the answer. A lake with adequate access but a limited recreational fishery is useless. It's no different than a lake with a tremendous fishery but no access. We simply don't know how much more information we can provide to the Corps and other controlling entities to understand the situation and the challenges we face."

One needs to look no further than Lake Oahe in South Dakota to understand the effect of significantly reduced smelt populations on a Missouri River reservoir.

In the mid-1990s, South Dakota Game, Fish and Parks Department biologists estimated there were 44 pounds of smelt per acre in Oahe. In the flood year of 1997, about 440 million smelt were flushed through Oahe Dam near Pierre as the Corps made a desperate effort to move spring runoff through the system.

Spring drawdowns since 1997, to accommodate downstream barge traffic, have hampered smelt reproduction and prevented the population from recovering. Game, Fish and Parks Department biologist Wayne Nelson-Stasny told the Sioux Falls Argus-Leader newspaper that smelt numbers are now down to two pounds per acre.

The result? From 1993-97, the average walleye caught on Lake Oahe was 17 inches and chunky. By 1999 and 2000, the average walleye size had declined below 15 inches and the fish were noticeably skinny, according to Nelson-Stasny.

Steinwand said smelt populations in Sakakawea have already declined about 50 percent the past couple of years and the effect of that is already being seen in the lake's walleye population.

In an effort to raise Lake Sakakawea's level to 1,825 feet or higher this summer, North Dakota attorney general Wayne Stenehjem said recently the state plans to sue the Corps. A spokesman for the Corps said even if the lawsuit is successful, maintaining higher water levels in the lake might be impossible because of the drought.

"We need something to happen now," Hoeven said. "We are going to see an impact that will adversely affect this world-class fishery for years to come."

Ironically, if anglers can access the lake this summer they should find pretty good fishing. Power, the Game and Fish biologist, said less water and reduced forage could equal success for walleye fishermen who can get on the lake.

"Short-term, if you can get out there, you'll probably catch some nice fish," he said. "Long-term, it doesn't look so good."

Perhaps the only thing that can "Save Lake Sak" is unexpected high amounts of snow or rain in the next few months. Fastabend, the Corps' brigadier general, reminded those in the Garrison City Auditorium that water levels on the Missouri River a decade ago were only a little higher than they are now.

"We estimated then it would take three to five years for the system to refill. It refilled in three to five weeks during the great flood of 1993," Fastabend said. "That was an unusual year, but this is a basin characterized by dynamic runoffs. It could be years. It may be weeks."

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