Weed-Eating Fish 'Vital To Reefs'
Scientists have suggested that protecting fish that graze on weeds may be vital in preventing the destruction of the world's coral reefs at the hands of unwanted vegetation. Weed-eating fish such as parrotfish and surgeonfish can clear up weeds around coral reefs up to a certain point, according to new study by Andrew Hoey and David Bellwood at the Centre of Excellence for Coral Reef Studies (CoECRS) and James Cook University. The paper, published in the journal Ecology Letters, reports that the scientific community has been counting on these weed-eating fish to rescue reefs from the danger of weeds for several years, as the marine ecosystems battle other threats like bleaching, cyclones, climate change and the dumping of sediment into oceans. However, the study added that the fish are unable to consume weeds after the plants reach a certain density, and prefer to graze less weedy areas. "The whole system tips from being coral-dominated to weed-dominated," Mr Hoey said, according to a CoECRS statement. "In countries where people harvest the weed-eating fishes with spearguns, nets and so on, like Fiji, we are seeing a fundamental change in the nature of reefs from coral to weeds," Andrew says. "In Australia, where there is much less harvesting of herbivorous fish, the corals are in better shape and bounce back more readily from setbacks."