In one of the largest global studies of its kind, researchers conducted more than 6,000 reef surveys in 46 countries across the globe and discovered 15 'bright spots' – places where, against all the odds, there were a lot more fish on coral reefs than expected.
The study, published in Nature, aimed to figure out why these reefs were much healthier than expected and whether there are lessons to be learned about how to avoid the degradation often associated with overfishing.
"Given the widespread depletion of coral reef fisheries globally, we were really excited to find these bright spots that were faring much better than we anticipated," said lead author Josh Cinner from the ARC Centre of Excellence for Coral Reef Studies at James Cook University in Queensland, Australia. "These 'bright spots' are reefs with more fish than expected based on their exposure to pressures like human population, poverty, and unfavorable environmental conditions."
The study involved 39 scientists from 34 different universities and conservation groups, including three affiliated with Stanford's Center for Ocean Solutions.
"This approach is an effective way to extract the signal from the noise in global data on reef status," said co-author Larry Crowder, a professor of biology at Stanford, senior fellow at the Stanford Woods Institute for the Environment, and.science director at the Center for Ocean Solutions. "The emergent patterns show us explicitly what allows some reefs to perform exceptionally well and others to perform poorly. Knowing this can help us steer reefs to their most resilient state."
By virtue of the breadth of the survey, the researchers identified several characteristics that improved the state of coral reef ecosystems.
"Many bright spots had strong local involvement in how the reefs were managed, local ownership rights, and traditional management practices," said co-author Christina Hicks, an affiliated researcher at the Center for Ocean Solutions currently at England's Lancaster University.
The scientists also identified 35 "dark spots." These were reefs with fish stocks in worse shape than expected.
"Dark spots also had a few defining characteristics; they were subject to intensive netting activities and there was easy access to freezers so people could stockpile fish to send to the market," Hicks said.
This type of analysis of bright spots has been used in fields such as human health to improve the well-being of millions of people. But this is the first time it has been rigorously developed for conservation.
Bright spots were typically found in the Pacific Ocean in places like the Solomon Islands, parts of Indonesia, Papua New Guinea and Kiribati. Dark spots were more globally distributed and found in every major ocean basin.
The authors write that the bright spots offer hope and some solutions that can be applied more broadly across the world's coral reefs.
"Specifically, investments that foster local involvement and provide people with ownership rights can allow people to develop creative solutions that help defy expectations of reef fisheries depletion," Cinner said. "Conversely, dark spots may highlight development or management pathways to avoid."
Additional authors attached to the Center for Ocean Solutions included affiliated researcher Christina Hicks, and Jack Kittinger, an alumnus of the center's Early Career Fellow program.