Modelling environmental factors in a population in the example of Lates calcarifer (Barramundi)

Dr Sabrina Streipert (The University of Queensland)

Lates calcarifer, commonly known as Barramundi, is an iconic Australian fish that is not only attracting commercial but also recreational fishers. The Centre for Applications in Natural Resource Mathematics works jointly with the Department of Agriculture and Fisheries Queensland to provide a population model that can give estimates of the population and can manage the stock in an economically viable and yet sustainable manner.

At the core of each stock assessment lies a population model that, to the best of experts’ knowledge, describes the dynamics. Using previous findings as well as work-ing with Barramundi experts, allowed us to formulate an age-structured population model that includes not only age-dependent mortality but also environmental fac-tors. The aim of this talk is to present the mathematical model and the consequences of including these factors. The introduction of this talk covers commonly applied population models in fisheries science and, particularly, previously used models for Barramundi. This is followed by a discussion of the environmental factors for Barra-mundi before deriving a modified population model that accounts for Barramundi’s dependence on these factors. The implications of deviations from previous models will be discussed.

Although the specific choice of the environmental factors might not be generic, the alterations made to the previous population model are more general and can be applied to other species.