Crown-of-thorns sea stars pose a major threat to small marine protected areas. Photo: Cody Clements
By John Toon
For marine protected areas established to help coral reefs recover from overfishing, size really seems to make a difference.
In a study that sounds a new alarm for endangered corals, researchers found that small community-based marine protected areas may be especially vulnerable to attack by crown-of-thorns sea stars, which can devastate coral reefs. The findings, published in the journal PLOS ONE, don’t diminish the importance of protected areas but point to a threat that may emerge from the degraded areas that often surround healthy coral ecosystems.
“The marine protected areas that are enforced in the Fiji Islands are having a remarkable effect,” said Mark Hay, Regents Professor and Harry and Linda Teasley Chair in Georgia Tech’s School of Biological Sciences. “The corals and fishes are recovering. But once these marine protected areas are successful, they attract the sea stars which can make the small marine protected areas victims of their own success.”
The research was supported by the National Science Foundation, the National Institutes of Health, and the Teasley Endowment.
“Successful small marine protected areas are like oases in the desert that may attract the sea stars, which can move tens of meters per day from degraded areas into the more pristine areas,” said Georgia Tech graduate student Cody Clements, who conducted the research. “One of the potential benefits of marine protected areas was supposed to be protection against these outbreaks, but that didn’t seem to be the case in the areas we studied.”