Going Beyond Visible Light: Using Infrared to Monitor Chinook Salmon and Other Species in Turbid Waters

Monitoring the fish community is already a challenging feat even on the clearest of days and in the easiest of conditions.  Data collection can be time and cost intensive, water clarity can be dismal, methods to actively monitor fishes continue to grow more restrictive, and species are being categorized as imperiled across the world every year.  These conditions make passive monitoring methods even more attractive in the evolving world of fisheries.  In 2003, FISHBIO incorporated the Vaki Riverwatcher, an infrared camera monitoring system, into their repertoire of sampling methods to monitor adult fish passage at weirs.  Over the past 12 monitoring seasons, FISHBIO and Vaki have worked together to fine-tune, adapt, and evolve the Riverwatcher into a highly effective passive monitoring tool.  This technology is currently deployed on several rivers throughout the Pacific Northwest.  It can be adapted to fit into several structures including fish ladders and other passageways.  Data from the Riverwatcher can be used to characterize fish passage by species, lengths, and sex even in turbid water.  This tool continues to be beneficial in the long-term data collection of the fish community and has proven to be an effective application for fisheries management.