A study in a marine protected area in Belize has shown that fishing closures boost predatory fish populations, but don’t benefit herbivorous fish as much.
The fishing closures have aided in the recovery of barracudas, groupers, snappers and other predatory fish. Parrotfish, surgeonfish and other herbivores have only managed slight recoveries. The Belizean government has recently proposed a national-level ban on the fishing of parrotfish. The authors of the study note that this may be the key to reef recovery.
“The fishing ban in the fully protected portion of the lagoon was expected to result in an increase in predatory fish and—more importantly—herbivorous fish such as parrotfish that in turn reverse the degraded condition of algal dominance in this reef,” said Dr. Tim McClanahan, lead author of the study and head of WCS’s coral reef research and conservation program. “What happened was a recovery of predatory fish, but not of the herbivorous fish, a finding that is forcing us to come up with a more effective model of reef management and recovery. If the nation-wide ban on parrotfish is successful, then we can see if this type of large-scale management is the only effective solution for protecting coral reefs.”
The uneven recovery of species could be due to many potential factors. It is possible that the complexity of the local food web was underestimated. Additionally, it is possible that the size of the closure was too small. Finally, there may fishers who fail to comply with the ban.
“It is encouraging to see the recovery of large predatory fish such as groupers and snappers under significant pressure elsewhere in Belize, but the lagging herbivorous fish is a warning that there is no single solution to coral reef conservation,” said Dr. Caleb McClennen, Director of WCS’s Marine Program. “While no-take zones are critical, more comprehensive ecosystem-based management is essential throughout the range of targeted species for long term recovery of the entire Meso-American Barrier Reef.”
Copyright © 2012 by Marine Science Today, a publication of OceanLines LLC