UI Engineers Work to Aid Pacific Lamprey Migration Along the Columbia River
University of Idaho engineers, working with the College of Engineering’s Center for Ecohydraulics Research (CER), the Army Corps of Engineers, National Oceanic and Atmospheric Administration (NOAA) Fisheries, and Pacific Northwest tribal representatives have installed two Pacific lamprey (Entosphenus tridentatus) passage structures (LPS) at the Bonneville and John Day dams along the Columbia River. The LPS have been constructed to assist with lamprey migration and improve declining populations.
University of Idaho, Center for Ecohydraulics Research director Ralph Budwig, civil and environmental engineering professor Danielle Tonina, civil and environmental engineering graduate research assistant Hattie Zobott, and fish and wildlife sciences professor Christopher Caudill designed the LPS at the north shore of Bonneville Dam in consultation with NOAA Fisheries and tribal representatives and installed it with a grant secured by Caudill from the Army Corp of Engineers. A smaller team composed of Tonina, civil and environmental engineering student J. Channing Syms, and lab engineer Bob Basham installed a second LPS at John Day Dam also on the Columbia River.
The Pacific lamprey is an ecologically important fish species throughout the Pacific Rim as well as a being culturally significant to Pacific Northwest Native American tribes. The Columbia River Inter-Tribal Fish Commission has tracked Pacific lamprey populations over the past decade and noted a significant decline. Once lamprey returned to the Columbia in the millions, but in 2010 lamprey returns at Bonneville dam were recorded at an all-time low of 23,000.
According to CER director Ralph Budwig the first issue recognized by fish biologists contributing to lamprey decline was that existing Salmon passageways at Bonneville and John Day dams were designed to aid Salmon migration. These passageway do not accommodate the Pacific lamprey’s natural anguilliform mode of swimming and in particular the lamprey’s unique use of their disk mouth to climb through suction.
Secondly according to Budwig the engineering challenge in designing lamprey passageways was to figure out not only the best design to facilitate the lamprey’s natural inclination to climb but to solve the problem of integrating LPS into the complex design of Bonneville and John Day dams without effecting how they operate. This component of the project was very important to the Army Corps of Engineers who run both dams.
The resulting work is a unique series of aluminum ducts much like you’d find in any home or business heating and air condition system but much more complex and flowing with water. According to Hattie Zobbot, the CER civil engineering graduate student designer, there are three components to the U of I LPS, the climbing, traversing and resting sections. The climbing portions of the LPS are made up of ductwork 20 feet wide by 6 feet tall. The traversing sections are generally 9 feet wide by 6 feet tall and the rest boxes are approximately 30 feet by 30 feet by 30 feet. From the lamprey perspective they migrate along the bottom and edges of the river. They then naturally congregate at specific areas below the dam which is where a Lamprey Flume Structure installed by the Army Corp of Engineers collects lamprey and then interfaces with the multiple component U of I LPS system that facilitates climbing.
The work on lamprey passage at migration barriers on the Columbia River has earned U of I researchers the American Society of Civil Engineers (ASCE), Environmental & Water Resource Institute and American Fisheries Society (AFS) Bioengineering Section Fisheries Engineering Committee Distinguished Project in Fisheries Engineering and Ecohydrology Honorable Mention Award.