Scientists find out what fear looks like from space
- In what is believed to be the first research of its kind, scientists have used Google Earth satellite images to observe the indirect effects of behavioural interactions between predators and prey on the Great Barrier Reef
- The work has opened up the possibility of using the freely-available satellite images to develop an inexpensive conservation and management tool
While most of us could find no better use for Google Earth than checking out a holiday destination, scientists in Sydney have shown it can reveal a lot about the behaviour of marine life on the Great Barrier Reef.
In what is believed to be the first research of its kind, UTS marine biologist Dr Elizabeth Madin and colleagues have used Google Earth satellite images to observe the indirect effects of behavioural interactions between predators and prey in the lagoon habitat at Heron Island.
The results, published in the paper "Landscape of fear visible from space" in the first issue of the journal Nature Scientific Reports, have revealed distinct patterns of grazing halos – rings of bare sand devoid of seaweed – within the algal beds surrounding isolated groups of coral.
Grazing halos have been attributed by previous researchers to fish and/or urchin herbivory (seaweed feeding). These creatures are thought to shelter from predators within reefs and then make foraging expeditions radiating outwards.
In-situ lagoon surveys showed that algal canopy height increased with distance from reef edges and grazing experiments confirmed that herbivore grazing was responsible for these patterns.
The work indicates that herbivores' collective anti-predator behavioural patterns can shape vegetation distributions that are clearly visible from space.
"To our knowledge, this is the first time anyone has used freely-available Google Earth images to identify these features, and then actually tested them on the ground to confirm that we're seeing exactly what we think we're seeing from the satellite images," Dr Madin said.
"This is significant because it could potentially lead to the development of a conservation tool which is both rapid and inexpensive. For example, by comparing sequential Google Earth images over time, the cascading, indirect effects of predator removal – say through fishing or the establishment of a protected reserve – could be monitored nearly anywhere on Earth."
Dr Madin is one step closer to realising the potential conservation and management applications of this research with the announcement that she is the 2011 recipient of the World Wildlife Fund's (WWF) Fuller Postdoctoral Fellowship.
The Fuller Fellowship, which honours the work of former president and CEO of WWF-US, Kathryn Fuller, supports early-career scientists working on issues of exceptional importance and relevance to conservation. Importantly, fellows have the opportunity to link their research to WWF's on-the-ground conservation work and to interact with WWF scientists and practitioners.
"The WWF Fuller Fellowship will enable me to continue this research into the future to explore if and how this approach can be used to help solve pressing issues in marine conservation and resource management, in particular understanding the large-scale effects of fishing and marine reserves," Dr Madin said. "I'm thrilled to receive this honour and look forward to working with people in both the global conservation and scientific communities to make this happen."
Dr Madin is currently a US National Science Foundation (NSF) Postdoctoral Fellow within the School of Environment and is a core member of the Centre for Environmental Sustainability and the Fish Ecology Lab.
The research was funded by the NSF and the Australian Research Council. Co-authors on the Nature Scientific Reports paper were Dr Joshua Madin from Macquarie University and Professor David Booth from UTS.
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