When there’s invading seaweed in your neighborhood, who you gonna call? Well, a new study by scientists at Georgia Tech shows that when corals are threatened by toxic algae they use chemical signals to call for help from their “bodyguards”, the unassuming goby fish.
The study, carried out on coral reefs in Fiji and published in the November 8 issue of the journal Science, shows that within moments of the coral’s “911 call” the gobies respond to these chemical distress signals and pick off the offending seaweed. What’s in it for the fish? Gobies spend their entire lives with the same patch of coral, using it for protection from predators and even feeding on mucus produced by the coral. It comes as little surprise then that the goby takes any threat to its shelter very seriously.
"The fish are getting protection in a safe place to live and food from the coral," said Mark Hay, a biology professor at Georgia Tech and the study’s co-author. "The coral gets a bodyguard in exchange for a small amount of food. It's kind of like paying taxes in exchange for police protection."
For one species of goby, feeding on the toxic algae has the secondary effect of making the fish itself more toxic to predators.
Coral is under threat worldwide from pollution and ocean acidification from human activity. When corals are stressed, aggressive algae competing for sunlit patches of ocean floor can represent a death blow to coral reefs and the magnificent ecosystems they support. At least one fish, though, isn’t letting the reef go down without a fight.
Almost a year ago we told you about Oceana supporters Neville and Catherine Hockley, who for the past four years have been circumnavigating the globe on Dream Time, their 38 foot sailboat. They left behind their lives on land to pursue their passion – exploring the world by sea.
So far they have sailed a whopping 16,000 nautical mile and done some incredible things: they’ve swum with humpback whales in Niue, free-dived with giant manta rays in Fiji, and visited the enchanted islands of the Galapagos. The couple also writes articles about their travels, and the proceeds go towards Oceana’s work to protect the oceans.
They shared with us some of the thousands of gorgeous photos they have taken, and we wanted to share them with you too: