Much of the Caribbean's iconic coral reefs have suffered a staggering decline due to climate change-driven bleaching events, local pollution and overfishing of ecologically important grazing fish. New research from the University of Queensland (UQ) warns that new science-based fishery regulations are needed to save the region's coral reefs.
The study, led by Dr. Yves-Marie Bozec, focuses on one herbivorous fish in particular: the parrotfish.
Parrotfishes, distinguished by their brightly colored bodies, are vital to the survival of coral reefs, as they feed on seaweed and algae that would otherwise smother and kill corals.
"While several countries in the Caribbean have taken the bold step of banning the fishing of parrotfish (including Belize, Bonaire, Turks and Caicos Islands), parrotfish fisheries remain in much of the region," explained Bozec, a researcher from UQ's School of Biological Sciences and the ARC Centre of Excellence for Coral Reef Studies.
So, the researchers decided to examine how parrotfish were affected by certain rates of fishing. They also analyzed the role of parrotfish in coral reef ecosystems.
"We conclude that unregulated fisheries will seriously reduce the resilience of coral reefs," Bozec added. "However, implementation of size limits and catch limits to less than 10 percent of the fishable stock provide a far better outlook for reefs, while also allowing the fishery to persist."
Extreme fishing throughout most of the 20th century brought parrotfish populations to the brink of extinction in many Caribbean regions. Following this decline, a number of countries attempted to modify their fisheries and reduce subsequent impacts on the region's coral reefs.
"What we've done is identify fisheries' policies that might help achieve this," said Professor Peter Mumby, co-author from UQ's School of Biological Sciences.
The new study recommends using science to revise current policies regarding the fishing of herbivorous fish species. In other words, researchers argue that the region's total parrotfish biomass needs to be calculated in order to better asses how many can be sustainably harvested without causing unfavorable effects on corals.
What's more is that the study authors have provided tools to help fishery managers make the appropriate changes.
"Ultimately, the more we do to maintain healthy coral reefs, the more likely it is that fishers' livelihoods will be sustained into the future," Mumby said. "We already know that failure to maintain coral habitats will lead to at least a threefold reduction in future fish catches."
The findings were recently published in the Proceedings of the National Academy of Sciences.
