Hydroelectric dams, flood control projects and navigation locks present obvious impediments for migrating fish. Assessment of fish passage at these structures is fundamental to understanding the effects of the impediments on fish populations. We have extensive experience applying sonar technologies to assess passage timing and fish behavior at hydroelectric dams and navigation structures.
Our experience conducting fish passage and behavioral studies includes an assessment characterizing post-passage behavior of adult salmonids at Lower Granite Dam in 2016. In that study we used ARIS in combination with a dual-axis rotator to assess behavior of fish upon entrance into the forebay and within the near-forebay environment during operation of a temperature control structure. Funding was provided by the U.S. Army Corps of Engineers, Walla Walla District and this work was done in collaboration with Anchor QEA, and University of Washington.
Fish passage research in the Columbia/Snake River hydrosystem has been almost entirely focused on Pacific salmonids over the last several decades. However, given the recent decline in the numbers of returning adults, Pacific lamprey has become an important species of concern for agencies stakeholders. The U.S. Army Corps of Engineers, Portland District funded studies (2011-2012) in which we collaborated with the University of Idaho to use DIDSON to assess lamprey passage at fishways in Bonneville and John Day Dams on the Columbia River.
Adult lamprey observed falling back through a fish ladder entrance at Bonneville Dam:
Keefer, M. L., P. N. Johnson, E. L. Johnson, T. S. Clabough, C. T. Boggs, W. T. Nagy and C. C. Caudill. 2017. Inter-observer bias in fish identification and enumeration using dual-frequency identification sonar (DIDSON): a Pacific lamprey case study. Northwest Science Vol. 19 (1):41-53.
With U.S. Army Corps of Engineers, Seattle District funding we conducted fish passage investigations at the Chittenden Locks (1997 through 2004) including an assessment looking at potential entrainment of adult salmon into a saltwater drain:
Contact us if you would like to discuss fish passage projects and the potential use of sonar tools for assessing fish passage and fish behavior.