Fig. 1. Relationship between the difference in variance at two harvest times and simulated bias of the two RGR estimators. Results are from a fully factorial array of simulations using six levels of RGR (0·05, 0·10, 0·15, 0·20, 0·25, 0·30 g g^–1 d^–1) and eight levels each of and (0·1, 0·2, 0·3, 0·4, 0·5, 0·6, 0·7, 0·8). Each point represents the mean of 10 000 simulations with a sample size of ten individuals in each harvest. The continuous line shows the bias as estimated by eqn (5).