A photograph of a shark eating a lionfish taken in East End this month may be an indication that sharks are beginning to hunt the invasive species in Cayman’s waters.
However, experts caution that this is likely a rare exception to the rule.
Lionfish populations have exploded on Caribbean reefs, threatening the entire marine ecosystem because of their voracious appetite for juvenile reef fish. They have no natural predators in the Atlantic, although divers have recorded grouper, sharks and eels occasionally feeding on lionfish.
Simon Morley, who took the photograph, said the shark appeared to be hunting the lionfish at a time when no culling was going on in the vicinity.
Bradley Johnson, environment officer with the Department of Environment, said the image provided further proof that predators were occasionally preying on lionfish without direct human intervention. But he said it was likely that the shark had been conditioned by human culling on that site.
He said it was not realistic to believe that lionfish were currently a frequent source of food for reef sharks in Cayman’s waters.
“It is interesting, but we have to wait and see what happens. A couple of incidents don’t make it a rule,” he said. “If sharks were eating lionfish on a regular basis, we wouldn’t see so many of them on the reefs.”
Steve Broadbelt of dive operation Ocean Frontiers, which organizes regular culls on the reefs around East End, believes lionfish are actually more abundant on reefs frequented by sharks, partially because interest from sharks in the culling activity makes the job more difficult.
He said diver culls are the only proven way to keep lionfish numbers in check.
“Something is eating the lionfish, but I don’t agree that it is the sharks,” he said.
“We are seeing a lot less lionfish than ever before. What we are doing with culling is working, but now is not a time to take our foot off the gas. I look at lionfish as weeds and no matter how nice your garden looks, if you ignore it, the weeds will come back. “Ocean Frontiers has culled over 10,000 lionfish and we serve lionfish tacos at our bar and grill. The sizes are getting smaller and the numbers much less.
“The Department of Environment is continuing to do a fantastic job in supporting the volunteers. The time has come not to rely so heavily on volunteers and a longer term strategy needs to be looked at next,” he said.