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Sarah
02-03-2009, 07:44 AM
January 31st, 2009

SAVANNAH, Ga. -- Jumping flippers-first into choppy, gray water 20 miles off the coast, divers from the Georgia Aquarium set off on a lionfish hunt.

They dove 90 feet to the base of a giant, yellow Navy tower where corals and sponges thrive and fish congregate.

Their quarry was at once beautiful and dangerous. And it turned out to be all too easy to locate.

"As soon as we hit the bottom we found one," said Jeff Reid, the dive safety officer for Georgia Aquarium. "As soon as we got it we saw another and got it. Then we saw two more but we spooked them."

In three 20-minute excursions, pairs of divers armed only with nets and a cage made from a plastic trash can surfaced with nine lionfish, a venom-packing predator from the Indo-Pacific the likes of which most Atlantic Ocean critters have never seen before.

Divers captured another 10 lionfish at and near the tower the next day.

The collections made in January left only 21 more to nab for a planned invasive-species exhibit scheduled to open April 1 at the Georgia Aquarium in Atlanta.

With fan-like fins forming its mane, the maroon and white striped lionfish could become the king of deepwater reefs off the southeastern U.S.
"They're a big problem," said Gail Krueger, outreach coordinator for Gray's Reef National Marine Sanctuary. "They're voracious and they eat everything. And what they like to eat best is baby grouper and snapper."

Gray's Reef, a national marine sanctuary near the collection area, saw its first exotic lionfish less than two years ago. It's somewhat protected from an all-out invasion because its more shallow waters - about 60 feet - get colder in the winter than lionfish prefer.

But that could change."We expect that these fish will probably adapt to cooler water as time goes on," said George Sedberry, sanctuary superintendent. "Right now they don't seem to be surviving the winter."
Other protected areas are already affected. The South Atlantic Fisheries Management Council has declared some shelf-edge reefs in very deep water to be off limits for bottom fishing, which creates a haven for the invasives, Sedberry said."The lionfish are going to be protected along with snappers, groupers," he said.
Divers can only spend limited time in such deep waters, making it hard to collect lionfish there. There's no other solution on the horizon."Knowing what we know now, it's going to be an impossible task," Sedberry said.

Lionfish are native to the Indian and South Pacific oceans, where fish such as eels, sharks and large groupers keep them in check. Not so in Atlantic waters, where the locals haven't evolved to be wary of lionfish. A 2008 study indicated a single lionfish on a small patch reef in the Bahamas could wipe out nearly 80 percent of native fishes in just five weeks. "These things are like a plague of locusts, they're so abundant and so voracious," said Mark Hixon, professor of zoology at Oregon State University and co-author of the study. "Fish in the Atlantic have never seen them before. They don't even see them as fish, that's the scary part."

Sharks and groupers don't investigate them as prey, and juvenile fish are like lambs to the slaughter.
"Small fish don't even do anything. They take no evasive action," Hixon said. "They'll be sitting there in a school and a lionfish comes up and it's like, 'Oh, Bob's gone. Oh, Ed's gone.'"

Lionfish are believed to have made their way to East Coast waters - with sightings as far north as Rhode Island in summer months - with a little help from the aquarium trade.
"The going theory is that after a hurricane an aquarium facility in Florida lost containment and a small population got into the ocean," said Akira Kanezaki, assistant manager of aquarium acquisitions at the Georgia Aquarium. "Realistically, home hobbyists probably purchase them because they think they're cool, then they get too big for the tank and they release them." Gray's Reef, which helped organize the lionfish hunt, is glad to be rid of as many as possible.

The Georgia Aquarium plans to educate about lionfish so home hobbyists won't release more and divers will know to beware.

The array of up to 18 spines on the top of the lionfish can deliver a painful, sometimes nauseating - though not deadly - sting. Experts advise those who get stung to treat the affected skin with water as hot as can be tolerated.

Kanezaki and his colleagues handled the fish with armored gloves, pincturing each one with a needle through the abdomen to relieve it of air that expanded in its swim bladder as it was brought to the surface. Without this micro-operation, the fish swim upside down, unable to right themselves.

How best to control lionfish remains uncertain. A program in the Bahamas encourages eating them.
"They're closely related to rockfish," Kanezaki said. "They're delicious."And cooking denatures their venom.
"They're also rumored to be an aphrodisiac in Asia," Hixon said. "That's a good rumor to spread. Get people's egos to save the reef."

He plans to study what controls lionfish populations in their natural habitat and see if analogous species in Atlantic waters can be fostered.

Still, he thinks lionfish are here to stay.
"The only real way to control them is on a reef by reef basis," he said. "You have to send out divers to collect them. I don't think we'll ever eradicate them."

source: Savannah Morning News

shinek
02-03-2009, 08:04 PM
Interesting, I had heard of them being spotted on the East coast, but didn't realise the numbers were getting that significant. How long before they are all over the Caribbean? The issues of water temperature described in the article would not be a problem for them a little further south.

Not the first invasive species to cause problems and certainly won't be the last.

Mind you, they are beautiful creatures, we spent a night dive looking at them on a trip to Kosrae, Micronesia and couple of years ago