The Lionfish


Guy Harvey

It was a great day for diving, with good visibility and a slight current from the east was pushing the blue chromis and creole fish up against the high spot on the wall. A couple of yellow mouth groupers were there, plus some dog snapper and a tiger grouper.

Something caught my eye that was out of place, a fin with striking markings poking out from under a plate coral…. a lionfish. It was sitting hidden under the coral overhang, facing the gentle current but secure in its position, waiting for an unsuspecting creole fish to come too close.

You can imagine the confusion among the other reef critters… what is this, never seen one before and then… wham, sucked down.

Lionfish do not get very big, about 18 inches, but have wide mouths that allow an adult to inhale a variety of common reef fish and crustaceans.

I had talked to people who had seen them here, but had not previously encountered one myself. The staff at Sunset House had shown me a couple including one juvenile about three inches long.

My first encounters with lionfish were on the Great Barrier Reef, Australia. There they are a fish we actively search for in order to take photos. They are fish of the Indian and western Pacific Oceans and are fairly common, occurring as several different species, but all are heavily striped and characterised by the separated venomous spines on the dorsal fin. Spines are for defence only and are not used in feeding. The venous toxin on the spines is not strong enough to kill a human, but can cause local discomfort, inflammation and swelling.

The large, striped pectoral fins are used for corralling prey into corners in the reef where the lionfish feed on small fish. In the daytime they are usually holed up under coral branches, sometimes in small groups. Their bright colours and vivid stripes have made them one of my favourite fish to paint.

These physical characteristics have made the lionfish a target for aquarium collectors and so they, like many other Indo-Pacific reef fish, can be found in aquariums around the world.

It is claimed that their introduction into the western Atlantic and Caribbean was through the destruction of a distribution facility on the coast of Miami during hurricane Andrew in 1992. Since then lionfish have thrived and multiplied having no natural predators in the Caribbean. Their eggs and larvae are carried on the ocean currents allowing them to settle in new habitats where they devour the inhabitants. Potential predators did not recognise them initially and only recently have some lionfish started to show up in grouper stomachs in the Bahamas.

I was on a tiger shark research trip in the northern Bahamas in May, and we encountered several large lionfish on each dive. The mate on the live-aboard dive boat was quick to spear them, skin them and fillet them out for dinner. Sautéed in a little butter and seasoning, they tasted awesome, in fact just like Alaskan crab. There are now lionfish eradication tournaments in the Bahamas, that seems to be an effective way of culling the species while at the same time ensuring that catches don’t go to waste.

So what do we do about the lionfish we encounter here in the Cayman Islands? Unlike the Animals Law that protects the invasive green iguana, there is no such protection for the lionfish. According to Tim Austin of the Department of Environment, the lionfish is fair game. “The lionfish eradication programme we are running out of DOE is going very well. I am not sure what the numbers are but we have certified over 150 local individuals to recognise, safely and legally catch invasive lionfish in Cayman waters,” Austin said.

“The lionfish is a voracious predator that eats juvenile fish and crustaceans in large quantities. In the Caribbean they have no known native predators and can reproduce year round from a young age.

“They are generally resistant to parasites and grow quickly, effectively out-competing native species for food and habitat. Lionfish constitute a broad-scale threat to marine biodiversity in the Cayman Islands and throughout the Caribbean.

“Given the inherent difficulties of eradicating rapidly reproducing species from the marine environment, and the ever-present potential for re-seeding of cleared areas by regional populations, it is unlikely that lionfish will ever be eradicated from the Cayman Islands and as such an ongoing programme of local effective control has been employed by the DOE rather than to attempt a short term eradication,” Austin added.

“Through a partnership with the Reef Environmental Education Foundation and financial assistance from the local Governor’s office, a volunteer network of divers has been established in the Cayman Islands, to record and capture lionfish under the guidance of DOE staff. Future work will involve improving public awareness and maintaining the interest of volunteers through the establishment of annual, ongoing events to maintain impetus for action.”

Perhaps we could have a lionfish tournament here at some point. Armed with a couple of small nets with handles, the slow swimming lionfish can be easily scooped up, and transported to a boat. As spear fishing with Scuba gear is outlawed here, use of spear guns or Hawaiian slings to eradicate lionfish opens the door for abuse.

However, with the amount of diving that goes on in the Cayman Islands, it seems the invasion of lionfish could be contained.

Fish responsibly, dive safely.
Guy Harvey PhD.   WH