Professor Peter Mumby
Australian Laureate Fellow
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Research Interests
Before embarking on a research career, Peter Mumby spent two years designing marine reserves in Belize where he experienced, first hand, the limited scientific basis for such planning. This experience was highly influential in defining and driving his research, which has been dedicated to conducting applied science in support of the management of coral reefs. In 1997 he obtained a PhD in coral reef remote sensing and then used two post-doctoral fellowships to broaden his expertise into empirical reef ecology and ecological modelling. Today, Peter uses remotely-sensed data to scale up ecological models so that they are spatially-realistic and able to inform conservation decisions directly.
Mumby’s research has responded to the challenge of obtaining credible evidence of human impacts at appropriate scales. Obtaining such evidence is often difficult because the management issue occurs at a much larger scale than is tractable through conventional manipulative experiments. The large-scale clearance of coastal mangroves is a case in point; juvenile reef fish are often found in mangroves so will mangrove clearance – which is occurring at a faster rate than rainforest clearance – reduce the numbers of adult fish on coral reefs? While this may appear to be a logical outcome, alternative outcomes are possible such as juveniles increasing their utilization of other, non-mangrove habitats. Using remote sensing and field survey, Peter designed a study across Belize and Mexico that allowed his team to isolate the effects of mangroves on reef fish community structure and falsify alternative hypotheses or potential sources of confounding. An absence of mangroves was found to lead to local extinction of the largest herbivorous fish in the Atlantic and cause profound reductions to the biomass of many fish species.
In addition to understanding deleterious impacts of humans on marine ecosystems, managers also need to demonstrate the benefits of conservation actions at appropriate scales. Mumby and colleagues have studied the impacts of marine reserves on Caribbean reefs and discovered that the direct effects of protecting fish can have profound indirect effects on the ecosystem. For example, a recovery of parrotfish inside a well-managed reserve led to a reduction of macroalgae and concomitant increase in coral resilience. Thus, while the reserve benefits fish directly, the resulting trophic cascades also benefit the corals and therefore help ensure the delivery of reef-based ecosystem services.
Reef management is a spatially-explicit process requiring decisions on where to locate reserves, where to prevent coastal deforestation, and so on. Of course, the seascape is a complex environment with some areas experiencing greater levels of stress than others. Ideally, a manager would be able weigh the relative value of taking action at different locations but this is fraught with difficulty: How can the outcomes of conservation actions be anticipated in the presence of multiple disturbances, each acting at a different scale and with different impacts? To address this problem Mumby has developed mechanistic ecological models of coral reefs that integrate reef dynamics, conservation actions, and disturbance including climate change. Models play an important role in synthesizing available scientific knowledge and using it to answer practical questions. So far the model has provided insight into the consequences of conserving herbivorous fishes, reducing nutrient runoff, conserving mangroves, and restoring urchin populations. These results have influenced reef management policy and led to new fisheries regulations.
Peter’s move to the University of Queensland will allow him to forge new collaborations in Australia and build models of climate change impacts on Pacific ecosystems.
