Bermuda's waters are under threat from a venomous Pacific fish with no business being in the waters of the Atlantic.

The lionfish — which can deliver a nasty sting — used to occur exclusively in the Indian and western Pacific oceans.

However, in recent years they have been observed in the western Atlantic, from Florida to New York and around Bermuda.

According to local experts, sightings have shot up in recent months — with one fisherman reeling one in by hand at the weekend.

Scientists are unsure what damage the introduction of lionfish might cause to the Island's reef ecosystem — and Government announced yesterday that a study has been launched.

It is believed lionfish were accidentally introduced, most likely by marine aquarium hobbyists, to the waters off the coast of Florida where they have now become established and are spreading.

It is thought the specimens turning up in Bermuda floated here as eggs and larvae from the southeast US.

Jennifer Gray, Biodiversity Strategy and Action Plan Coordinator at the Department of Conservation Services, said: "We're seeing a lots of these fish turning up.

"Divers are seeing them in deeper water and there have been quite a few found closer in. They are extremely venomous. The venom comes from the spines when you handle the fish. It won't kill you but it will be pain you don't want to know."

According to Ms Gray, the fish caught by Brian Hollis and friends Dennis Lamb Jr and Michael Simons on Sunday is believed to be the first reeled in by a fisherman, although lobster fisherman have reported spotting them in lobster pots.

Mr. Lamb Jr. hooked the creature two miles off Mid Ocean Beach in about 70 ft of water.

Mr. Hollis, 47, later contacted Ms Gray for advice as — despite having fished since he was five years old — he was not sure what it was.

"We could see it was something funny and thought we'd better not bring it aboard. It looks pretty dangerous. We got a little photo then released it," he told .

"The spines themselves indicated it's not a fish to grab onto but I didn't realise it's as poisonous as they say it is."

In response to the lionfish invasion, the Department of Conservation Services will be collecting specimens found locally to determine what they could do to the reef ecosystem.

These will be examined to determine whether they are actually breeding in Bermuda's waters and what they are eating.

Dive guide and doctor David Wakely said the lionfish in Bermuda's waters — whose scientific name is — would feed on smaller fish, potentially "wiping out an entire generation of up-and-coming reef fish".

But he said that was less of a problem than the impact on the fish who act as cleaning stations. If they are affected, larger fish who rely on them to be cleaned could die out due to parasites. "It's quite a large knock-on effect," he said.

A Government spokesman said: "To help us with this, we would like to keep track of where the lionfish are being observed by members of the public.

"If you see a lionfish when you are snorkeling or diving could you please, as soon as possible, contact the Marine Conservation Officer at 293-4464 extension 146 or email lionfish[AT]gov.bm.

The information we need from you is the date you saw the lionfish, location and depth of where you observed it, the approximate length (snout to tip of tail) of the fish; also your name and telephone number in case we have any further questions."

Although the hospital has not yet received any patients suffering from lionfish stings, the spokesman offered advice to anyone injured. "Seek medical attention immediately.

"While you are waiting for medical treatment, elevate the affected limb and immerse the site in hot (not scalding) water, as hot as can be tolerated, for an hour or until the pain stops," he said.

Dr. Wakely said the venom from the lionfish was not especially dangerous but the pain would cause a victim to hyperventilate and feel generally unwell.

Putting the affected limb in hot water breaks down the protein and speeds recovery.

"For fishermen the easiest thing to do is put your hand in the stream of the outboard motor as long as it's not scalding," he added.