Cesium Kinetics Data for Estimating Food Consumption Rates of Trout

Abstract

The data from a cesium kinetics experiment in a natural semi-drainage bog lake were used in estimating the rate of food consumption and the rate of cesium excretion by rainbow trout (Salmo gairdneri) which inhabit the lake. Estimates of the 133Cs retention half time and food intake were shown to vary greatly throughout the year. For example, based on observed data and theoretical considerations, trout consumed only about 0.5% of their body weight daily in mid-winter but up to 8% in early summer. In addition, cesium retention half times ranged from about 100 days in summer to 850 days in mid-winter, based upon water temperature, body weight and growth.