SIMULATION STUDY OF SALMON CARCASS SURVEY CAPTURE-RECAPTURE METHODS

Population estimates are made on a hypothetical salmon (Oncorhynchus sp.) spawning run by a capture-recapture survey of fish carcasses by simulation. The Petersen, Schaefer, and Jolly-Seber models are used under various combinations of survival rates, catch rates, and tag rates. All model estimates are least affected by different levels of tag rates. The Schaefer model population estimates are sensitive to changes in survival and catch rates. The Petersen model consistently overestimates the population. The Jolly-Seber model more closely estimated the simulated population. Great care must be taken in assessing the aptness of models in capture-recapture studies.