The Great Barrier Reef evolved over millions of years to support one of the most diverse collections of animals anywhere. But today its 7,700 square miles (20,000 square kilometers) of coral communities are threatened by sediment, pollution, crown-of-thorns starfish and shifts in temperature and chemistry [sources: ABC; UNESCO].
Now there's some good news, at least as far as coral trout (Plectropomus genus) are concerned. According to a 10-year progress report, the commercial fish have benefited significantly from a sixfold expansion of no-take zones begun in July 2004. The move, which upped the protected areas from 5 percent to nearly one-third of the study area, was controversial because some feared it would increase fishing intensity in nonprotected areas. Instead, trout in no-take zones grew beyond minimum catch sizes and, because larger trout tend to make more babies than smaller trout do, produced enough offspring to keep surrounding zones at break-even levels. Some evidence also suggests that reduced fishing around no-take zones helped coral recover because it reduced damage from fishing lines, which can scar coral and open it up to infection [sources: ABC; Milius].
Unfortunately, such programs might only work on individual commercially fished areas. In parts of the world where survival is a catch-as-catch-can prospect, poaching, loopholes and other regulatory challenges persist. Meanwhile, global warming remains the single greatest threat to reefs worldwide [sources: ABC; Milius].