Making equations from the interplay of nature and economics

Published 13 March 2019

What does a bioeconomist do?

Looking at UNE bioeconomist Professor Oscar Cacho’s history of research interests does not immediately help explain his work. At various times Oscar has been deeply involved in aquaculture, livestock grazing, the farming of pet clams, invasive weeds, and carbon sequestration in forests. And other things.

These are the “bio” part of “bioeconomist”. They are biological systems, and as such they are dynamic; always in flux. The “economist” part of his job description refers to the human economic systems that exploit these biological systems.

Oscar’s work sits in the interface of these fields. Using mathematical models, he seeks order in the chaos that occurs between two dynamic processes, and finds patterns that support decisions — costs, risks, rates of population spread, the probability of achieving a goal.

As a discipline, bioeconomics is highly specialised. As a lens for viewing the world, it can be trained on many things to better understand how humans and nature interact.

“Most of what we do when we exploit or manage the natural world involves trade-offs,” Oscar says. “Do we develop this bushland, or conserve it? Do we turn an area of land into farms or national parks?”

“I’m looking at those trade-offs in ways that help us understand the consequences of taking one path or another.”

Asking these questions has taken him down some unexpected paths. During some work with the Australian Weeds Cooperative Research Centre, he was asked to look at the bioeconomics of environmental weeds.

“We modelled how they spread in the environment, how they choked out native plants and how they opened the way for other invasive species. We used models of population growth combined with economic models to look at how you could contain environmental weeds, and then eradicate them.”

“But then I was talking to an ecologist, and he said, ‘If you’re going to kill them you have to find them first’.”

That led to the scientific literature on search theory, and models initially developed by the US Navy to hunt for submarines – later adapted for search-and-rescue operations.

“It gave us a way of measuring the detectability of our target, which allowed us to weigh up the probability of finding it against the effort and cost of searching for it.”

Oscar built the results into software, Weed Search, that continues to help those assessing the costs of weed control. It also took him to projects on the Galapagos Islands, western Queensland and currently, Kosciusko National Park.

Bioeconomics has also led down other unexpected paths — for instance, to the Solomon Islands, where one of his PhD students studied whether growing giant clams for household aquariums in California could help the island economy. It came down to how often the Islanders were prepared to scrape algae from the clam cages to ensure they could photosynthesise and grow.

Elsewhere in the Pacific, Oscar has used his tools to assess whether island communities can reverse deforestation trends by developing agroforestry funded by carbon markets.

“The places I’ve been, the things I’ve seen — it’s not what you expect an economist to be doing.”

His path into bioeconomics came from putting one foot after the other.

Growing up in his native Mexico, Oscar loved the work of pioneering underwater explorer Jacques-Yves Cousteau. His first degree was in the field of marine biology. The field work was wonderful, but the job prospects for those without a postgraduate degree were less attractive.

Seeking a more secure outlook, and thinking it might lie in aquaculture, he moved to Auburn University in Alabama, home to one of the best freshwater fishery research stations in the Americas. Pursuing studies in fish nutrition, he found himself grappling with other variables, like changes in water temperature and quality or oxygen levels.

Each variable affected the other in ways impossible to foresee with mere human intelligence.

Looking to understand how these things could be visualised and managed, Oscar took units in Economics. He’d had no previous interest in the subject, but it captivated  him. When he did his PhD, it was on the economics of aquaculture.

That done, “I wasn't going to go back home and grow fish anymore. There were many other interesting problems to tackle.”

A job came up in New Zealand’s Lincoln University looking at the bioeconomics of rotational grazing. He took it. And in 1994, he took a position of lecturer in UNE’s Department of Agricultural Economics.

Bioeconomists are still rare, and Oscar finds the number of students thinking towards a career in the field is relatively low.

It’s not an area of study for undergraduates, he believes. It’s for the post-graduate who has a degree in a discipline, say ecology, and who then finds a whole suite of questions not answered by their skill set and looks to a Masters in economics.

“That’s when I come along. We start looking at the problem they're trying to tackle, and then we start with some very simple model, developing the mathematics, looking at the conceptual relationship between different parts of the system. And we expand from there. It’s like an apprenticeship.”

He would welcome more students who are not afraid of equations. One of his best students was working for the OECD in Paris (and is still there) while assessing the greenhouse gas footprint of livestock for his PhD research.

“What we do is applied. We solve problems. We just need more people to be aware that you can solve problems this way.”

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