688 



Fishery Bulletin 94(4), 1996 



occurred when measurement and process error were 

 included in the simulations, the Kalman filter and non- 

 linear least-squares biomass estimates were positively 

 biased and appeared positively skewed. 



We interpret these results to mean that the 

 Kalman filter method provides superior performance 

 in terms of RMSE but provides biased biomass esti- 

 mates. This is a serious problem for a stock assess- 



