The Shape of Recruitment Distributions

The shape of recruitment distributions in marine fish is generally assumed to be lognormal on the basis of empirical evidence and theoretical argument. If recruitment is considered to be an outcome of the probability of survival of individuals or groups of individuals which may contribute to the year class, then it can be shown that the underlying distributional shape will depend on the degree of survival independence and may be nearly symmetrical for bet-hedging species. The underlying distributional shape may be obscured by estimation error, which may suggest a greater degree of positive skewness than actually exists.