The majority of lacustrine fish populations in the western USA are located far from the nearest
road. Although mark-recapture techniques are widely accepted for estimating population
abundance, these techniques have been broadly ignored for fisheries surveys in remote mountain
lakes because of restricted access and associated logistical constraints. In this study, mark recapture experiments were used to estimate fish population abundance in nine small (< 7 ha)
lakes of the North Cascades National Park Service Complex. Fish in the mark sample were
collected by angling, fin-clipped, and immediately released; fish were recaptured with variable
mesh monofilament gill nets. A single-census Petersen estimator was used to calculate
abundance in each lake, and assumptions for unbiased estimates appeared to be satisfied in
most cases. Post-release mortality of angler-captured fish was low. The small size of these lakes in conjunction with the brief period of rime allotted for each individual experiment apparently reduced the probability of unequal vulnerability and mortality for marked and unmarked fish. Single-census mark-recapture experiments appeared to provide reasonable estimates of population abundance in these mountain lakes. Resulting estimates furnish a substantial increase in information when compared to more ubiquitous assessments of relative abundance, but the logistical requirements are modest. We believe that this technique may useful for survey purposes in other small, remote lakes.
