Sharks “taught” to eat poisonous lionfish on Cuban reefs


Image credit: National Geographic

HAVANA, Cuba, Tuesday September 30, 2014 – A Cuban diver has come up with a novel way of controlling rising numbers of invasive lionfish by feeding them to the sharks off the coast of the communist Caribbean country.

A venomous and voracious intruder, the IndoPacific lionfish poses a serious threat to coral reefs in the Caribbean, Florida, the Gulf of Mexico, Central America, and northern South America.

Beautiful but deadly, these fish have the potential to disrupt coral reef ecosystems as predators that out-compete most other species for food resources, yet have few known natural predators of their own to keep their numbers in check.

Cuban diver Andres Jiminez is nevertheless working on plans to level the playing field.

A demonstration of the courageous diver’s strategy was photographed by French marine biologist Mathieu Foulquie during a trip to Cuba’s popular tourist attraction the Gardens of the Queen National Marine Park.

“The pictures show the hunt for lionfish, and demonstrate how local guides are trying to control the invasive species by training sharks to eat them,” Foulquie told Britain’s Daily Mail.

“My diving instructor, Andres Jimenez, who is also a marine biologist, shot a lionfish with his pole spear and presented it to the Caribbean reef sharks swimming around us.

“One of the sharks swam directly towards him to catch the lionfish.

“The lionfish is an invasive species in the Caribbean, but native Caribbean predators like sharks, or grouper fish don’t eat them.

“If the sharks can be taught to consume them, however, they will naturally regulate them.”

At a depth of twenty-five-metres, Foulquie watched as Jiminez carefully caught the lionfish and fed it to the shark, an experiment which has been in practice since 2011, according to the Daily Mail.

The Frenchman nevertheless stressed the “Don’t try this at home” caveat.

“Only specialists in shark behaviour can try this kind of experiment, and ordinary divers and photographers should never try to feed them.

“From a scientific point of view, we don’t know how successful the project is. But, apparently, recent videos show native top predators are starting to eat lionfish without them being previously speared by divers,” Foulquie added.

A reduction in lionfish numbers is essential given that their diet consists of numerous shrimp, crabs, and other crustaceans, including juveniles of the commercially important spiny lobster. They are also responsible for great reductions in fish numbers on reefs where they become established, and prey on herbivorous fishes that consume macroalgae and help protect corals from algal overgrowth.

A critical issue in controlling their numbers is their huge reproductive potential and age of reproductive maturity, moreover.

National Oceanic and Atmospheric Administration (NOAA) researchers have determined that lionfish reach sexual maturity within two years and spawn multiple times during the spawning season, which may be year-round. Each spawn can produce up to 30,000 eggs.

Scientists believe that lionfish populations will continue to grow and are unlikely to be culled by conventional means.

Due to their fecundity, rapid and widespread distribution, adaptability to a variety of shallow and deep habitats, and behaviour, it is thought that the lionfish invasion places coral reef ecosystems throughout the Americas at significant risk.

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