Lionfish plague threatens Bahamian economy

Gladstone Thurston, The Bahamas Weekly 21 Mar 10;

MARSH HARBOUR. Bahamas -- The explosion of lionfish population in Bahamian waters is “a plague of biblical proportions stalking the Bahamian economy,” the Reef Conservancy Society of Abaco is warning.

They are convinced that unless urgent action is taken it will wreck tourism, fishing and related industries.

It has now been confirmed that lionfish, known for their voracious appetite for Bahamian marine life, have been decimating fish that tend the coral reefs.

The loss of herbivorous fish sets the stage for seaweeds to potentially overwhelm coral reefs and disrupt the delicate ecological balance in which they exist, studies show.

Following on the heals of over fishing, sediment depositions, coral bleaching, and increasing ocean acidity, “this is of grave concern,” said renown zoologist/marine biologist, Dr Mark Hixon, a professor at Oregon State University.

Dr Hixon and his group work from the Perry Institute for Marine Science, Lee Stocking Island, Exuma. They have a three-year grant from the US National Science Foundation to study lionfish.

He warned that the rapid reproduction potential of lionfish must now be understood in context with their ability to seriously depopulate coral reef ecosystems of other fish.

It is well documented that over fishing parrotfishes and other herbivores contributes to the death of reef-building corals. Lionfish are “highly effective” at ‘over-fishing’, he warned.

The Conservancy said Bahamians ought to be alarmed as this strikes to the heart of tourism, fishing and related industries on which the economy of the country stands.

“Tourists come here to see the turquoise waters, they come to fish and dive and enjoy the beautiful reefs,” stated the Conservancy. “If theses things go, there will be no reason for tourists to come anymore. And tourism with its spin-off industries is the very foundation of our economy.

“When there are no fish out there to clean the reef, the reef dies and the water turns a dark green; dead rubble is covered by seaweeds.

“Tourists who come for the sun, sand and sea will stop coming. Divers are not going to spend all that money to come here to look at dead reefs. There will be no more bonefishing and fishing tournaments. Restaurants will have to close. People will be out of work. It will be chaotic.”

South Abaco Member of Parliament Edison M Key said he was “extremely concerned” since a substantial amount of the Abaco work force is engaged in tourism, commercial fishing and support industries.

The Conservancy’s warning was made all the more dire as lionfish have already started to invade nursery habitats in mangroves and creeks where marine life breed.

“We found that a single small lionfish can reduce the number of small fish on a small reef by about 80 per cent in just a few weeks,” said Dr Hixon.

His expertise is the ecology of coastal marine fishes in temperate and tropical regions. He has studied reef fish in The Bahamas for more than two decades. His research was interrupted in 2007 by the arrival of lionfish.

In an interview Saturday, Dr Hixon told of other significant findings.

“We are not finding many native species that seem willing to try to control lionfish naturally,” he said. “We have tried feeding lionfish to large groupers and sharks and they do no seem interested.

“Native predatory fish do not seem to recognize lionfish as even being fish because lionfish look so weird, and then when they do take a bite they get a mouthful of venomous spines, so that is a deterrent.

“Moreover, unlike native Bahamian fish, invasive lionfish have almost no parasites.”

Red lionfish ( Pterois volitans), native to the Pacific, were first sighted in The Bahamas in 2005.

Having never existed here before and not facing controls normally faced in their native Pacific region, they are reproducing on an unheard-of scale, said Dr Hixon.

Scientist, Dr Isabelle Cote, a professor at Simon Fraser University, reported finding nearly 400 per 2.5 acres (hectare) here.

With their reddish and whitish stripes, a row of spines down their backs, and fan-like fins, these beautiful creatures are easy to spot. Every spine of the lionfish is venomous. While no fatalities have been reported, their venom is extremely painful.

Lionfish tend to grow larger in The Bahamas, investigations show. Football-size specimens have been reported. Only one of the 15 or so species in the Pacific has been spotted here.

A “key question,” said Dr Hixon, is whether whatever keeps lionfish in check in the Pacific can be employed here using native Atlantic species.

“We are working on that right now,” he said. “All we can say at this point is that whatever naturally controls lionfish and keeps them in check in their native Pacific is very effective, because they are rare there.

“They occur over a broad range of the tropical Pacific but they are minor players, which is vastly different from here in The Bahamas where they are everywhere.”

One of the best ways to control lionfish is to develop an industry for its edible meat, he said. As cooking de-natures the venom and the tissue is not toxic, it could be advertise as a conservation dish.

Already lionfish meat is a hit in high-class restaurants in Chicago and New York. It is said to taste similar to snapper.

“If we can encourage fisheries in The Bahamas and see that lionfish are well advertised in the United States where restaurants are already serving them, then I think we will have a good thing going,” said Dr Hixon. “It would benefit Bahamian fishermen and help save the reefs.”

It is uncertain whether lionfish will ever be eradicated from this region.

“The effort should focus more on control,” he explained. “There are so many lionfish, and they occur at so many depths and in so many habitats that complete eradication seems unlikely to me.

“However, if we are able to implement some strong controls on them and Mother Nature steps up – let us say a parasite or a disease does attack the lionfish – then perhaps they could be eradicated.”

A good thing about lionfish is that they are easy to locate and capture.

“In a localized area, like a popular fishing reef,” he said, “it is a simple matter of divers going down with hand nets and sweeping the area periodically.

“It is another reason for encouraging a fishery. It would be important because it would not just be people volunteering to save the reefs but people will be going down to catch lionfish to sell them.”

Abaco fishermen are alarmed that lionfish have found their way into the mangroves and creeks. A new paper has documented the same in San Salvador.

“That is really a serious problem - lionfish in the mangroves and creeks,” said Dr Hixon. “We have to figure out something to do about this invasion before it causes a major crisis.”