High Missouri Dam Releases Could Hurt Fisheries

Originally published in the Dickinson Press on May 6, 2011
Click here for original link
by Associated Press

Fishery managers in North Dakota and South Dakota are nervous about anticipated high water releases from upstream dams on the Missouri River this summer.

The Army Corps of Engineers has said this could be a year of record runoff into the river system that stretches from the mountains in Montana to Missouri, where it empties into the Mississippi River. The Fort Peck, Lake Sakakawea and Lake Oahe upper basin reservoirs are all but full, and dam releases this summer are expected to be higher than they have been in 14 years, The Bismarck Tribune reported.

Fisheries officials in the Dakotas are worried about the effect on rainbow smelt, a main food for game fish such as walleye, when summer releases hit the projected range of 49,000-54,000 cubic feet per second.



"In 1997, summer releases were in the upper 50s and a very large proportion of Oahe's rainbow smelt population were lost downstream," said Greg Power, fisheries chief for the North Dakota Game and Fish Department.

Lake Oahe, which is in both Dakotas, took years to recover, officials said.

"By the spring of 1998, we were seeing a lot of skinny fish," said John Lott, fisheries chief for South Dakota's Department of Game, Fish and Parks.

By 1999, South Dakota had removed the 14-inch minimum for walleyes. By 2001 it had adopted a daily limit of 14 walleyes in an effort to remove the smaller fish from the system.

Today, Lott said, Oahe has a more diverse forage base with perch, white bass, drum and gizzard shad but still retains a four walleye daily limit with only one keeper longer than 20 inches.

"We are still trying to restore balance," he said.

Power is worried about the smelt population and also bank erosion, with Lake Sakakawea forecast to reach an elevation slightly above 1,852 feet above sea level.

"Last year, it peaked at 1851.4 feet, which was the fourth-highest summer elevation on record and caused very significant erosion on the adjoining uplands," he said.