Abstract
A method is presented to estimate relative recruitment from catch-at-age data alone by applying fuzzy control theory. An important feature of this approach is that the natural mortality coefficient is not needed. Simulation tests were conducted to determine the performance of this approach including comparison with a conventional method. The simulations showed that the assumed trend of recruitment was well reproduced. The fuzzy method possessed a higher robustness to noise in the catch-at-age data than the conventional method. This approach is useful for the analysis of catch-at-age data.
