No-take zones protect more than just fish


An Australian scientist has found that no-take marine reserves that ban fishing protect more than just the fishes alone.

Reporting in a recent issue of the journal Current Biology, Hugh Sweatman compared the frequency of Crown-of-thorns starfish (Acanthaster planci) outbreaks on no-take reefs and on reefs that were open to fishing on the Great Barrier Reef.

The study, which was based on results of an extensive monitoring program, found that there were fewer starfish outbreaks in the no-take zones (the Crown-of-thorns starfish is a notorious predator of corals and outbreaks are known to denude coral reefs or living coral), with outbreaks in the fishing zones as much as 3.75 times higher than in the no-take zones.

The link between the increased presence of commercially valuable fishes and the reduction in numbers of Crown-of-thorns starfish is not clear, but the author speculates that the larger numbers of large predatory fish in no-take areas reduce the densities of benthic carnivorous fishes such as wrasses, which in turn allows invertebrates that prey on very small crown-of-thorns starfish to thrive and reduce starfish numbers.

For more information, see the paper: Sweatman, H (2008) No-take reserves protect coral reefs from predatory starfish. Current Biology 18, pp. R598"R599.