When one of themany threatsto coral reefs overwhelms them , the location is normally whelm by seaweed , making restoration many clock time harder . However , Cancer the Crab may be process to the rescue , at least if we give them a little assist .
Seaweeds thrive in the atomic number 7 and phosphorus runoff that can pop coral Reef offshore of intensive agriculture . Many fish eat seaweeds , and corals have even been found torelease chemicalsthat attract these when jeopardise by seaweed takeover . Unfortunately , efforts to spawn piscean grazers rarely keep up with rapid growth in these condition , particularly after an nameless disease wiped out ocean - urchins , another seaweed consumer . However , Professor Mark Butlerof Florida International University reckon the reply may lie in Crab ' menacing claws .
Butler has observed Caribbean king crabs ( Maguimithrax spinosissimus ) not only eat on a plenty of seaweed off the Florida Keys , their dieting includes types of seaweed other animals rule poisonous or laborious to digest . On the other hand , M. spinossimusare just not an abundant enough species to deal with seaweed outbreaks that menace reef habitats , credibly because of high puerile depredation .
InCurrent Biology , Butler and PhD student Jason Spadaro report the achiever of a trial to boost crab turn on Reef mostly brim over by seaweed . Single - handed ( or should that be exclusive - claw ) bitch reduced seaweed cover version from 85 percent to below half . Where aqualung divers removed seaweed prior to the crab ' dismissal , seaweed area fell by 80 pct after a yr . Meanwhile on control reefs , where crab numbers were low , seaweed mastery did n’t commute .
Removing the seaweed would be reasonably counterproductive if coral did n’t deliver to fill the gap , but two age later coral and Pisces were 2 - 5 times as abundant on crab - rich reefs as the controls .
" When Jason showed me the results he had compiled from our first year of experiments , I could n’t think it – they face too good , " Butler said in astatement . " You should have check the expression on Jason ’s face when I say , ' Nobody will believe these event . We have to iterate the experiment for another year at another location . ' Not incisively what a grad student want to hear when trying to finish up ! But we did it and the results were the same . "
Butler and Spadaro transplanted crab from other Reef , rather than breeding them , so while they think crab farming will make for , they do n’t yet make out for certain . If it proves possible to hike up stock , it will not be a bit too shortly for the realm ’s Witwatersrand , most of which have undergo a phase - shift to seaweed supremacy . Butler mark the barrier Rand along the Keys has less than 2 pct of its original coral back . Without activity to undertake climate change , Butler warned nothing is potential to save the remain fragments , but the Crab could at least give them a combat prospect to outlive long enough if the world does get serious .
Maybe it ’s just as well crustacean keepturning into crabs .
