ASFB Home > 2003 > Biological Invasions: Consequences for Parasites, Pathogens, Emerging Diseases, and Fisheries in the Marine Environment.

A Time-varying Parameter Fish Migration Model

Elkana Ngwenya and Hannah Muhar

Faculty of Fisheries and Marine Environment, Australian Maritime College, P.O Box 21, Beaconsfield, Tasmania, Australia 7270
Email: e.ngwenya@fme.amc.edu.au

The importance of migration of aquatic species is recognised in fishery management literature. Various spatial and temporal models of fish migration are used in the analyses of fish behaviour and their implications for fisheries management. It is generally recognised that fishery management decisions often give less consideration to fish migration. This paper presents a framework for analysing fish migration using a predator-prey system in which the model parameters vary over time. In this framework selected environmental and biological variables are introduced. These selected variables are incorporated into an equation structure, and generate expected time-varying parameters through regression analysis. The resulting equation models and time-varying parameters are used to capture the effects of selected environmental and biological variables. Simulation results of population dynamics likely to arise from a time-varying parameter predator-prey model are reported. The simulation results are compared with results from alternative fish population migration models. The time-varying predator prey model has implications for stock assessment.

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