Recognizing that non-parametric methods to estimate fish stock recruitment are generally
simple and they do not need to be based on ecological hypotheses, four non-parametric
methods; the probability transition matrix and three algorithms to estimate recruitment
probability density functions were tested on cod (Gadus morhua) data from NAFO Div. 3NO.
The transition matrix method was inadequate because the cod stock failed to meet the
primary Markovian assumption: the transition probability must be constant and depend only
on the previous state. Of the three algorithm methods, the fixed-interval, the New England
and the Cauchy, only the New England was appropriate for calculating recruitment with these
stock data. A regression coefficient of r = 0.556 (d.f. = 23, P = 0.003) was obtained when the
observed data were compared with the estimated. The validity of estimates of future
recruitment using the New England algorithm depends on biotic and abiotic environmental
conditions being similar in both the pre-recruit and the observation periods
