Mathematics to improve environmental management

Poaching and Illegal Wildlife Trade

Even the simplest ODE models of harvest can produce a rich set of population dynamics when we account for the motivations of humans hunting for and trading wildlife products. Conservation scientists have started using these models to inform policy to protect species against illegal harvest. We've shown that many models can produce dramatic bifurcations, with small changes in parameters or initial conditions driving healthy populations extinct. Yet, we have very few general rules for when we expect to see different types of mathematical behavior. This can be disastrous, as it is hard to determine whether the projected environmental outcomes are simply the result of numerical error, coding bugs, arbitrary model assumptions, or are robust and general accross systems. One of my on-going lines of research is to develop rigorous mathematical descriptions of population dynamics of harvested species within a broad class of mathematical models.

The value of model complexity for fisheries management

More than 99.8% of fisheries are assessed using single-species models. Since humans harvest multiple interacting species, not considering these interactions can lead to negative outcomes that reduce food security, eliminate human livelihoods, decrease economic production, and harm the environment. This project aims to quantify the benefits of using multi-species systems of ordinary differential equations for harvest decisions. Expected outcomes of the project include 1) guidance for fisheries scientists on when to use multi-species models for management, 2) improved decision making to reduce the risk of fishery collapse, 3) a new method for dynamic model validation in the face of limited data.

Fishery Sock Assessments

I regularly apply mathematical and statistical theory to improve fisheries management in collaboration with the Queensland Department of Agriculture and Fisheries (DAF), and the Australian Fisheries Management Authority (AFMA). For example I performed the first stock assessment of coral trout, a collection of species (Plectropomus leopardus, P. maculatus, P. laevis), in the Torres Strait. Most of my fisheries management work focusses on methods for data-poor fisheries where the status of the fish stock is highly uncertain.

How to best feed the world?

Can we sustainably feed a rapidly growing global population? How do we eliminate hunger with the least environmental harm? Improving the management of harvested populations can play its part, but we also need to better manage agriculture and livestock production. I am broadly interested in projects that tackle these questions using system dynamics, optimisation, and data.