This is really odd: there just might be a stable population of lionfish off the cost of Long Island. Many moons ago, I used to be a marine ecologist, and I would have never considered the notion that a tropical fish would be able to maintain an overwintering population even in Long Island Sound (which is a little warmer than the Atlantic Ocean). It’s not clear if the population actually overwinters, since mostly juveniles have been found; however, the number of juveniles suggests that there is more than one breeding female. I’m wondering if there is the possibility that a cold-tolerant mutant could arise. On a more serious vein, it would be interesting to compare the cold tolerance of adults in the northern part of their novel Atlantic range with those in their native tropical Pacific habitat.
This weirder than the time I was diving near Groton, and I saw a barracuda.
From the Grey Lady:
Long Island’s waters are being invaded by the exotic lionfish, an alien tropical species native to the Pacific Ocean that has vividly colored stripes and a freakish array of venomous spines.
Divers report capturing hundreds of lionfish this summer, compared with a total of about 30 over the last three years.
“For us to be finding that many, there must be thousands and thousands more out there,” said Todd R. Gardner, a biologist at Atlantis Marine World aquarium in Riverhead. “It’s a population explosion.”
Apart from the novelty of lionfish and the mystery of how they wound up so far from home, the sudden proliferation also raises questions about effects on the ecosystem, including potential threats to indigenous fish and hazards to swimmers.
“That’s really the $2 million question: What are they eating and what are they competing with for habitat?” said Paula E. Whitfield, a biologist at the National Oceanic and Atmospheric Administration, which is studying the phenomenon with Mr. Gardner and the University of North Carolina.
For now, the strange species is a draw at the aquarium. “It’s a flamboyant fish,” Mr. Gardner said. “People walk into the room and run right to that.”
For the worried, the good news so far is that all the odd-looking visitors are pale babies and are expected to die off when the cooling sea drops below 50 degrees in the fall. But the fish are voracious eaters, feasting on Long Island’s already diminished shellfish and fin fish as they grow to five inches long during their detour here.
“All you have to do is look at their full bellies,” Mr. Gardner said. “They look like they’re going to explode.”
And even in the juvenile stage, the fishes’ hollow hypodermic-like spines and venom sacs inflict nasty — but not deadly — stings. “It’s very painful, a burning pain,” said Mr. Gardner, who has impaled a finger.
One pet-store worker required surgery to save a badly swollen arm after four punctures from an adult lionfish, Mr. Gardner said.
Experts advise prompt medical attention and immersion of the wound in hot water to weaken the venom.
Every year, the Gulf Stream sweeps tropical fish north, and some of them inevitably veer off to the New York region, delighting researchers, divers and fishers.
But lionfish are not native to this hemisphere, at least not until recently. A few appeared in Florida in the mid-1990′s, followed by occasional sightings along the Carolinas and Georgia.
Those few fish were adults, prompting speculation that they had been released by pet shops, suppliers or hobbyists, or that they had escaped somehow. Inadvertent transport in ship ballast is another possibility, but experts discount it.
Scientists were stunned in 2001 with the discovery of evidence that the lionfish, whatever their origin, were spawning in the Atlantic. That discovery came when Mr. Gardner, then a graduate student on a field trip, found a tiny lionfish clinging to a dock piling in the Great South Bay by Fire Island.
“I was absolutely shocked,” he recalled. Coming up for air, he wondered: “How could there be a lionfish here in New York? It was just not registering, not making sense.” He dipped back underwater. “Sure enough, he was still there, and I caught it.”
His perplexed professor accused Mr. Gardner of using a pet fish as a prank, but it was so tiny that it could not have come from a store. Others suggested mistaken identity, but the lionfish is unique with its vertical stripes of white alternating with a deep maroon or rusty color.
Skepticism melted a week later when Mr. Gardner captured another baby at the same site.
Other divers and researchers were finding adult lionfish established on reefs and shipwrecks off Southern states. Reports trickled in of hatchlings carried on currents as far north as New Jersey and Rhode Island.
Still, Mr. Gardner’s many dives off Long Island never found more than a dozen or so lionfish in any season — until this year. “They’re very easy to catch,” he said. “I don’t even use a net, because they don’t scare very easy, because they have such an effective defense system. I just carry a Ziploc bag and scoop them up.”
Some recreational divers have started collecting lionfish for home aquariums, Mr. Gardner said, and one diver offered to sell 39 to a pet shop in Patchogue.
The local lionfish were found in the bays along Suffolk’s South Shore, but not in the open ocean, so bathers at the major beaches were not at risk. And even in the bays, the fish congregate at underwater rocks or pilings, so waders are unlikely to bump into them or step on them, said Stephan B. Munch, who teaches at the marine sciences center at the State University at Stony Brook.
With a long history of tropical fish like grouper, snapper and jacks straying to Long Island, “it’s really unlikely that lionfish are having any more impact than the others,” he said.
Lionfish grow to 18 inches and, while they have no known predators in the wild, Mr. Munch said he had lost one specimen to its hungry tankmate, a grouper. Ms. Whitfield, the biologist with the oceanic administration, said they are eaten by people in the Philippines, and are starting to be eaten in the Carolinas.
One crew collecting lionfish for the federal study tried grilling some of its catch of the day. “They said it was good, a mild white flesh,” Ms. Whitfield said, though she did not sample it herself. “I’m allergic to fish.”