NDGF News Release

Lake Sakakawea Chinook Salmon and Rainbow Smelt Update

Of the quarter-million chinook salmon planted in the Missouri River System in June by the North Dakota Game and Fish Department, 200,000 were released in Lake Sakakawea and 50,000 in the Garrison Dam Tailrace. Another 50,000 chinook salmon will be stocked in Sakakawea in October.

During years with ideal water levels, salmon will commonly grow to 8-10 pounds before being caught by anglers. Growth has been noticeably poorer in recent years because of low water levels and a declining rainbow smelt population, the primary forage fish for Sakakawea’s salmon. For this reason, 50 percent fewer salmon than usual were stocked in Sakakawea in spring because of low smelt numbers.

The smelt population has followed Sakakawea’s waters levels, both falling since 2000. The last three years, lake levels have been at record lows – about 25 feet lower than ideal – negatively influencing smelt reproduction and survival.

Salmon and smelt need deep, cold water to survive. Low lake levels in recent years have significantly reduced the amount of coldwater habitat in the big lake. In July 2005, the U.S. Army Corps of Engineers implemented a modification to Garrison Dam’s intake structure in an effort to conserve coldwater habitat. The modification will remain in place as long as reservoir levels remain low.

In spring 2006, the corps improved smelt spawning conditions by raising Lake Sakakawea’s levels by two feet during and immediately following the spawn. Despite the rise, recent sampling by State Game and Fish Department fisheries biologists indicate that smelt reproduction was poor.

The likelihood of producing a good smelt year-class in Lake Sakakawea is better when water levels are above 1,825 feet above mean sea level during the spawning period. Below 1,825 msl, quality smelt spawning substrate – rock and rubble – is lacking. Lake levels the last three years have been at record lows as summer highs have reached only about 1,817 msl.