Reducing effects of dispersal on the bias of 2-sample mark-recapture estimators of stream fish abundance
Fig 5
Empirical distribution of Chapman’s estimator in simulations with the modified sampling scheme.
Study-reach length is 90 (arbitrary units), study-reach abundance n = 300, sample-2 capture probability q′ = 0.1, 0.3, 0.5, 0.7, sample-1 capture probability q = 1 − (1 − q′)3, and maximum movement distance δ = 0, 30, 60, 90. Sample-1 capture probabilities ensure sampling effort (duration of sampling) is the same as in sample 2. Dispersal is balanced. Other symbols and lines are defined as in Fig 3.