Improved Salmon Escapement Enumeration Using Remote Video and Time - Lapse Recording

We developed a remote video escapement recording system to enumerate adult salmon (Oncorhynchus spp.) as they enter their natal streams to spawn. The system is small, relatively lightweight, easily deployed, and operates under its own solar, wind, or hydrogenerated power, depending on site characteristics. In 1999 we deployed a remote video escapement recorder on Delight Creek, the outlet of a clear water lake system on the Outer Coast of the Kenai Peninsula that supports a modest sockeye salmon run (10,000-30,000 fish). Our objective was to determine the reliability and accuracy of the remote video escapement recorder for estimating sockeye salmon escapement into a small stream. The recorder successfully operated 87% of the time it was programmed to run. Daily video counts of total fish passage tracked very well with daily weir counts of the same, particularly after mid-July when subtle modifications to the video system dramatically improved image quality. After these improvements, the remote video escapement recorder documented 85-87% of the total fish passage counted through the weir. While further refinements are expected, we concluded that remote video and time-lapse recording systems are capable of collecting relatively accurate and reliable sockeye salmon escapement estimates.