Boise, Idaho (KMVT-TV) Idaho Power biologists have begun a three-year survey of white sturgeon in the Snake River below Hells Canyon Dam and a portion of the lower Salmon River.

From now through November, they will use setlines to catch these giant prehistoric-looking fish that have changed little over the past 175 million years. Sturgeons are the largest freshwater fish in North America and can weigh as much as 1,500 pounds and reach lengths of more than 12 feet.

The sturgeon will be weighed, measured, scanned for the presence of an electronic tag, cataloged and released.

The purpose of the study is to update population data for white sturgeon in this reach, and implement a standardized monitoring program that tracks sturgeon abundance by assessing the population every 10 years. The information gathered will be important for monitoring the long-term success of white sturgeon in Hells Canyon.

“This is the largest monitoring effort for sturgeon that Idaho Power performs,” said Idaho Power Senior Biologist Ken Lepla. “We are targeting this population because it is one of only two productive, self-sustaining sturgeon populations remaining in the Snake River upstream of Lower Granite Dam.”

Crews are using baited setlines, gear that is commonly used in white sturgeon studies throughout the Columbia River Basin. The setlines are rigged with “circle” hooks that prevent sturgeon from swallowing the hook because of its unique shape. This gear has been used in Idaho Power’s white sturgeon surveys over the last 20 years without incident to sturgeon, and the field crews strive to maintain this record.

Each setline is marked by an orange buoy and metal tag identifying the study and Idaho Power’s contact information. All setlines are checked daily and at frequent intervals. The public is asked to avoid contact with the setline gear; tampering or vandalizing the gear may cause unnecessary harm to fish if the setlines cannot be recovered.

The survey is part of Idaho Power’s White Sturgeon Conservation Plan, which provides for periodic monitoring of sturgeon populations associated with our hydroelectric projects. It has been 10 years since Idaho Power last surveyed fish in this area.

This survey is conducted in coordination with state, tribal and federal entities including the Idaho Department of Fish and Game, Oregon Department of Fish and Wildlife, Washington Department of Fish and Wildlife, Nez Perce Tribe, U.S. Forest Service, and Bureau of Land Management. The company’s plan includes sharing information with fish management agencies and cooperatively identifying measures to improve or maintain populations of this great fish.