Conservation planning for Great Barrier Reef islands

It’s a classic conservation planning problem. There are hundreds of islands within the Great Barrier Reef World Heritage Area with ecological values of national and international significance. Serious threats to those values are posed by invasive plants and animals, and there are limited people and money to manage the threats. How should the conservation dollar be spent?

Professor Bob Pressey at JCU said the goal of the GBR islands program was to produce decision-support tools for the managers of the islands (QLD Queensland Department of National Parks, Recreation, Sport & Racing and the Great Barrier Reef Marine Park Authority). An important outcome is that the managers will be able to come up with investment plans that have a stronger evidence base than in the past, making them more cost-effective and accountable.

Pressey said the project team is creating software that the National Park islands managers can interact with using a GIS interface. He said, “We hope it will reveal conservation priorities that have not yet been identified. However it also allows an adaptive approach, where the data that are influencing “decisions” are easy to see and can be improved if something doesn’t make sense.”

Conservation planning is a relatively young science and the software is constantly evolving to allow more sophisticated scenarios. Pressey said, “We want to approach the complexity of real-world decision-making. That means being able to set priorities in time and space and to allow for multiple management actions in the same places.”

Goats, for example, are a non-native species on the GBR islands where control is expensive and not always fully effective. According to Pressey there are cases where National Parks have gone out and shot goats to blazes but not quite finished the job because the money has run out. Then the goats build back up again and the benefits are gone. Managers need to be able to ask complex questions such as; “How long should a control program run? and “Do we need continuity for eradication or does it make more sense to control every few years?”

Pressey said “We have found the managers can tell us a lot about how much control programs cost but there are significant gaps in our knowledge of the recovery of ecological values of importance after threat abatement. So we’re having to estimate as best we can.”

Developing criteria that establish clear links between management actions, threats and ecological values is an important outcome of the project. There are no historical baselines for most species. For seabirds, one the threatened species groups that are found on the islands, important criteria are whether nesting is restricted to the island and what other resources are utilised for food or habitat.

“We have compiled an extensive data base from published papers, grey literature and from the accumulated knowledge of people who know about the islands. For seabirds for example, we worked with an elicitation process to ask managers a series of questions about threats and about population estimates, habitat associations, and life-history traits of birds on the islands.”

The software development was possible because of a resource-sharing arrangement with a Western Australian project on the biosecurity of islands off the Pilbara coast. Pressey said, “We have an explicit set of criteria now that we can use to prioritise threats to the GBR islands and can also be used for other similar situations such as the islands off the Pilbara coast. It will get really interesting when people start interacting with the software. We have done the groundwork for a system that can evolve and improve with continued collaboration between JCU and the island managers.”