‘Maintaining fish stocks at certain level could help save coral reefs’Published On: Fri, Sep 30th, 2011 | Marine Biology | By BioNews
An international team of scientists have found a tool for managing corals reefs and tropical fisheries worldwide that could play a vital role in preventing the reefs’ collapse.
In their study the researchers demonstrated how overfishing can generate a predictable sequence of events that lead to the collapse of reef ecosystems.
“The consequences of overfishing can be severe to the ecosystem and may take decades to recover, but hundreds of millions of people depend on reefs for food and livelihoods, so banning fishing altogether isn’t a reality in many nations,” said Dr Nick Graham of the ARC Centre of Excellence (ARC CoE) for Coral Reef Studies and James Cook University.
“Our work shows that as fish biomass – the number and weight of fish living on a reef – declines due to fishing pressure, you cross a succession of thresholds, or tipping points, from which it is increasingly hard to get back.
“For example, you see patches of weeds replacing coral, you see more sea urchins devouring the coral, you see a general decline in the species richness on the reef, and you see less coral cover.
“The loss of hard corals is actually the last stage in the collapse of the reef system. Though many people take it as a major warning sign, in fact, by the time you see the loss of live coral cover, it may be already too late to save the reef,” he added.
Dr Aaron MacNeil from the Australian Institute of Marine Science also said that if fish stocks can be maintained at a certain level, the chances of retaining a sustainable fishery and a healthy reef system are greatly improved.
The study was published in the Proceedings of the National Academy of Sciences of the USA (PNAS).