A non-parametric approach to investigating fish population dynamics

The population dynamics of a fish stock can be investigated through knowledge of the stock-recruitment relationship and the replacement line associated with biological characteristics such as age growth, maturity and natural mortality. While functions defining the replacement line are generally easily formulated, it is more problematic to specify the stock-recruitment relationship. Using a non-parametric model for the stock-recruitment relationship it is possible to avoid defining specific functions relating recruitment to stock size while also providing a natural framework to model process error. This paper describes a kernal method approach to moadlling the recruitment data, that takes ito account uncertainty, which leads to an empirical method for investigating the population dynamics of exploited populations under a range of fishing scenarios.