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Sustainably Harvesting Nature

Sustainable seaweed industries

Scott Spillias is a PhD candidate at The University of Queensland exploring how large-scale seaweed farming will promote or hinder global and local sustainability objectives. He uses a variety of techniques, including stakeholder engagement and quantitative dynamic modelling to bring a more detailed understanding of the complex trade-offs that will arise from the expansion of seaweed farming as part of the Blue Economy.

Advisory team:

Eve McDonald-Madden, University of Queensland

Kate O’Brien, University of Queensland

Richard Cottrell, University of Tasmania


External Collaborations with researchers from: 

University of Tasmania

International Institute for Applied Systems Analysis

Melbourne Sustainable Society Institute 

Seaweed infographic.png

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 behaviour. 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 across systems. One of our ongoing lines of research is to develop rigorous mathematical descriptions of population dynamics of harvested species within a broad class of mathematical models.



Matthew Holden

Eve McDonald-Madden

Duan Biggs

Liam Timms (Honours student)

Jakeb Lockyer (Honours student)



Fisheries management and stock assessments


We 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, Matthew performed the first-ever stock assessment of coral trout, a collection of species (Plectropomus leopardus, P. maculatus, P. laevis), in the Torres Strait. Our work in fisheries management focuses on developing new methods to quantify uncertainty, optimize harvest given economic and environmental objectives, and inform and prioritize the development of new policy. 



Matthew Holden

Manuela Mendiolar (PhD student)

Montana Wickens (Honours student)

Prawn harvest_NOAA Fisheries West Coast_Flikr_CC BY-NC-ND 2.0.jpg

Prawn harvest. Image: NOAA Fisheries West Coast, Flikr, CC BY-NC-ND 2.0

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