Overfishing on coral reefs isn't simply caused by too many people, according to a new report published in the February 10th issue of Current Biology, a Cell Press publication. Rather, the researchers found that the biomass of fish found on coral reefs in the western Indian Ocean depended mostly on the complexity of the reefs themselves and the socioeconomic status of the people living on the shores.
Specifically, they found, overfishing is at its worst in areas that have climbed only part way up the development ladder. In such locations, fish numbers were only one quarter what they were in places with either higher or lower levels of development.
Moderately developed places often had a few amenities, such as roads, schools, and electricity, but were generally considered poor by global standards, said Joshua Cinner of James Cook University in Australia. While people there tend to depend less on fishing, they also have more access to engine-powered boats, spear guns, and other technologies that can rapidly deplete some fish species. Those locations also tended to have fewer traditional village rules to limit fishing and national governments that are too weak to effectively enforce fishery regulations.
"In short, they have the technology to plunder their reefs, but not the institutions to protect them or the levels of development that allow for sufficient alternatives to fishing," Cinner said.
The findings suggest that the sustainability of coral reefs will depend in large part on whether developing countries can improve their well-being without falling into a poverty trap, he added. A poverty trap occurs when communities are forced to degrade the very resources they rely on due to a lack of alternatives for making ends meet.
"Those conditions can create a cycle of poverty and resource degradation, and the danger is that, if pushed too hard, reefs may lose their ability to bounce back when and if economic conditions improve," Cinner said. "For communities already in a poverty trap, governments and donors need to help them get out and couple this development with good governance and strong institutions."
Cinner noted that the current economic crisis can actually offer a "window of opportunity" for western governments, non-governmental organizations (NGOs), and donors to restructure aid and conservation efforts to better tackle root causes of reef decline. While some coral reef conservation projects already do try to consider socioeconomic issues and provide people with alternatives to fishing, the new findings suggest that those efforts likely won't be enough, he added. "Reef fisheries don't seem to get better until very substantial improvements in human welfare have been made," he said.
The bottom line, he says: "While there are certainly some real challenges facing reefs, the path to their destruction is not inevitable. They can be sustained with the right combination of approaches, which includes promoting strategies such as fishery closures while at the same time tackling poverty as a root cause of the degradation of reefs and their fish stocks."
The researchers include Joshua E. Cinner, Australian Research Council Centre of Excellence for Coral, James Cook University, Townsville, Australia; Timothy R. McClanahan, Wildlife Conservation Society, Marine Program, Bronx, NY; Tim M. Daw, University of East Anglia, Norwich, UK; Nicholas A.J. Graham, Australian Research Council Centre of Excellence for Coral, James Cook University, Townsville, Australia; Joseph Maina, Wildlife Conservation Society, Marine Program, Bronx, NY; Shaun K. Wilson, Australian Research Council Centre of Excellence for Coral, James Cook University, Townsville, Australia; and Terence P. Hughes, Australian Research Council Centre of Excellence for Coral, James Cook University, Townsville, Australia.