Abstract

We estimate bioenergetics parameters using length-age and mark-recapture data for a stunted population of Northern pikeminnow on the Bonaparte plateau, British Columbia using a seasonal reproduction, skeletal allocation model. We show that using field data alone it was possible to estimate food consumption rates, standard metabolic rate and metabolic Q₁₀ parameters, the proportional increase in feeding rate per 10^o C increase (Q_c), but that prior parameter ranges must be specified. Using the estimated parameter set, we predict body sizes using warmer water temperatures from Cultis Lake, British Columbia and the John Day Reservoir, Columbia River. We show that surface temperature differences between the Bonaparte plateau, John Day reservoir and Cultus Lake alone are insufficient to explain very large under- predictions of body size for these areas. In addition to diet differences, fish are likely choosing between fine-scale temperature and food-density environments to optimize capture and metabolism of food.