Invader

As our diver’s boat is bobbing gently in crystal-clear, turquoise waters off the island of Great Exuma in the Bahamas, I make a few last-minute adjustments to my dive mask and snorkel. In a moment I will join marine biologist Mark Hixon on an underwater expedition to locate and capture a lionfish – so named because its fan-like fins resemble a lion’s mane – or, as the fish are known to tropical fish hobbyists, Pterois volitans.

Before we jump overboard, Hixon reminds me, “If we see one, keep your distance. These babies pack a wallop. A jab from their venomous spines could send you to the hospital. And the nearest one is a plane ride away.”

He smiles and asks me, “You’re not having second thoughts, are you?”

I’ve come to the Bahamas to spend time with Hixon as he investigates what he says may become “the most devastating ocean invasion ever”. He and other researchers are looking for ways to stop the explosive population growth of red lionfish, a non-native species eating its way through the Caribbean and other Atlantic waters.

“ ‘Explosive’ is a good word. And you can add ‘invasive’,” says Hixon as we sip Bahamian beers at the Perry Institute for Marine Science on Great Exuma’s Lee Stocking Island. Ten years ago, sightings of lionfish, which generally reach a size of 30-35cm, in Atlantic waters were rare. These maroon-striped beauties, which hide an arsenal of venomous, needle-sharp spines among their feathery, translucent fins, are native to the Pacific and Indian oceans, some 16,000km away from the Caribbean.

“Suddenly,” says Hixon, “they were being spotted in the Atlantic. It was like seeing a polar bear in Hawaii.” They didn’t swim there, he said, and there’s no evidence they arrived in ships’ ballast waters.

“So how did they get here?” I ask. Hixon smiles, sips his beer and tells me an amazing story – nobody can prove it happened – that begins in southern Florida in 1992 with the onslaught of Hurricane Andrew. That Category 5 storm, the century’s third most powerful, roared ashore in late August with winds over 250kmh and wiped out thousands of homes – and some aquariums.

“There were unconfirmed reports that it smashed one private aquarium that was home to perhaps six or seven lionfish,” explains Hixon. “These were released into Biscayne Bay [south Florida] and began doing what invasive species often do best; eating and reproducing.”