Lionfish New Explorers of the Caribbean Report of the 2011 Explorers Club Lionfish Flag 46 Expedition By Peter Rowe (FI 08) When we hear the word exploration we always, in our human-centric fashion, think of exploration by our own species. However we are not the only animal on earth that likes to go exploring. Of course many animals arctic terns, albatrosses, tuna, caribou, Monarch butterflies are natural wanderers. But in recent years we humans have assisted the travel of normally sedentary animals, either by building canals, polluting or warming the planet, or bringing them to new places by ship or plane. Once they have arrive, off they go, where no-one expected them to with successive generations of individuals exploring further and further afield. One of the most extraordinary stories of animal exploration is the lionfish, the wildly attired venomous fish that has exploded in population throughout the Atlantic and Caribbean. 15 years ago there were no lionfish in these waters. Today, there are millions one study estimates 1400 per acre of reef with a 1
range stretching from New York south to Venezuela. Within two more years, it is believed they will have made it as far as Uruguay. They aren t by any means the only fish off exploring new territory. Jumping Asian Carp You Tube favourites for their crazy antics are heading north up the Mississippi. A grey whale recently showed up off Israel, the first there in 300 years. And the melting of the Arctic means that Atlantic and Pacific Salmon may very well meet soon somewhere in the Northwest Passage. However the story of the lionfish Pterois Volitans - is unique both in terms of the speed of their explosive growth and the potential for damage to their new adopted home. The danger from the lionfish comes not from its venomous spines although those spines on the ends of their pectoral and dorsal fins are easily strong enough to kill a fish or send a person who is touched by them to hospital with stings much worse than a bee or wasp. The issue is more the lionfish s ravenous appetite. A single lionfish can eat through 80% of a patch reef s inhabitants within 5 weeks virtually destroying the ecosystem. In the spring of 2011 I led an Explorers Club Flag Expedition to investigate the lionfish invasion. We began by travelling to Jupiter Inlet, Florida, to dive with Florida International University lionfish researcher Zack Judd, and Florida Divemaster Randy Jordan founder of Lion Tamers USA. Jordan, like many people running dive operations in Florida, the Bahamas and Caribbean, seems almost obsessed with the lionfish threat., with a kill count (the day we dove with him) of 375. They are the perfect predator, he tells us, while steering his dive boat out into the Gulfstream. They have no parasites, no diseases, no predators. They have the ability to eat every other fish and larvae in Florida.. Left unattended, within 5 to 10 2
years they would eat every other fish and there wouldn t be anything else down there other than lionfish. Jordan is the inventor of the Lion Tamer, a short spear gun specifically designed to shoot lionfish. He leads us on a hunt for the fish in 95 feet of water. They aren t hard to find and aren t hard to hunt. In fact, the expression, shooting fish in a barrel comes to mind. With no natural predators, they are not skittish, and as long as you avoid getting stung by the venomous spines, it is pretty easy to shoot 4 or 5 on every dive. But as a way of preventing the spread of lionfish, it seems a bit futile. The reefs and shorelines stretch for thousands of miles. Shooting a few individuals will never stem the tide, and experts now seem unanimous that eradication is now impossible. The fish can live anywhere from mere inches of water up to 1000 feet of depth, and researcher Zack Judd has found many specimens swimming well up the murky Loxihatchee River into brackish and even fresh water. Given our own photographic preference for crystal clear water, we took his word for it, but did attend the Loxahatchee River Center s annual Lionfish Fundraiser, where the locals in this swanky corner of Florida get dolled up to spend a Saturday night hearing about this problem newcomer to their state and dining on the delicious white meat that this fish produces once you get past the venomous spines! From Florida we moved on to dive with researchers at the Island Institute at the southern tip of Eleuthera in the Bahamas. With me were three of the most experienced lionfish researchers in the world, Lad Atkins of the Reef Environmental Education Foundation, based in Key Largo, Florida, Stephanie Green of Simon Frazer University s Marine Biology Department and Skylar Miller of the Island Institute, based on Eleuthera, and Explorers Club applicant student member Brianna Rowe. 3
The two questions that most interested our team were first, where did the fish come from, and second how did these relatively small fish manage to spread themselves over such a huge area, fighting against the powerful Gulf Stream to spread throughout the Caribbean. DND sampling of the fish suggests that they all come from a very small gene pool possibly as few as 6 fish, that that probably originated in Miami. How did they cross the Gulf Stream? The massive current has a flow 200 times that of all the rivers that flow into the Atlantic combined (yes, that includes the Mississippi, the St.Lawrence, the Congo and the Amazon). Off Florida, where its speed is greatest, it is hard enough to cross it in a sailboat let alone as a relatively tiny fish, with only a tailfin for propulsion It seems so improbable that the lionfish could swim south from Miami against the Gulfstream, that other theories about the origins of the fish abound. On the docks and beaches of the Bahamas, one hears the claim that that the fish were first released not from Florida but rather as eggs from the waste outflow of the huge aquariums at the Atlantis resort on Paradise Island. This theory makes much more geographic sense, since those eggs could easily be then swept down the Tongue of the Ocean into the Caribbean, but while it is a nice conspiratorial theory with a big bad Atlantis villain, it seems that it is not the case. The three researchers on our Eleuthera team have looked at the seawater waste systems at the Atlantis aquariums, and are convinced that the filtration systems prevent eggs or fry from being washed into the ocean. Instead, they are quite convinced the invasion did begin in the Miami area perhaps, from broken aquariums at Miami Seaquarium during Hurricane Andrew; more likely, simply by pairs of fish being released into the ocean by aquarists, tired of the voracious appetites of their spiny pets. 4
There are reverse eddies in the Gulfstream, and a reverse current flowing beneath it., as seen on these two charts. One must assume that some small percentage of lionfish or lionfish eggs were swept south down into the islands. It is a path as mysterious as that taken by some of the rubber ducks lost in the Pacific in 1992 that managed to make their way across the Northwest Passage into the Atlantic, but the odds are certainly in the favour. A female lionfish produces a gelatinous matrix of 30,000 eggs twice a week. By comparison, a female grouper produces the same 30,000 eggs once a year. However it started, by 2000, the invasion was well under way. As these charts show, at the turn of the millennium the fish were in Florida. By 2002 they were established in Georgia, the Carolinas and Bermuda. 5
By 2004 the fish had established a beachhead on Long Island, New York, and by 2006 another on Long Island in the Bahamas. By 2008 they were in Cuba, Hispaniola, Puerto Rico, Jamaica and the Cayman Islands, and by 2009 they were in the Yucatan Peninsula, Central America and Venezuela. 6
Today, there are millions of lionfish up to 1400 per acre of reef, by some estimates. By 2013, researchers believe they will have expanded south past Brazil to Uruguay. It took the original native human population thousands of years to spread through this vast area. Even with sailing ships, it took European explorers and settlers over 100 years to discover it all. It will take lionfish only 15 years to conquer the territory. And conquer it they do as researchers have become convinced that with their hearty appetites, ability to 7
live in degraded conditions and lack of predators, they are massively reducing the populations of other reef fish, thus drastically reducing the biodiversity of the Caribbean and Bahamian reefs. Only the cooler waters north of Cape Hatteras and south of Uruguay will prevent the fish from moving even further afield, and as the Atlantic warms up, who knows how far north and south the fish can get. Ironically, it took the lionfish ten years to make their way 40 miles south of Miami to the Florida Keys. Unable to swim directly into the fast-moving Gulfstream, they journeyed out hundreds of miles into the Caribbean and eventually, several years later, their offspring made their way back north to the Florida Keys. 8
As can be seen on this chart, the lionfish then quickly made their way through the Gulf of Mexico. They were not present in the Keys in January 2009, but within that year had moved right through them. By August of 2010 they had made their way north to Tampa, and by a month later were living in the oil platforms off the coast of Alabama and Louisiana. Our flag expedition to Eleuthera, in June of 2011 found lionfish on every dive. We dove to depths of about 100 feet on the reefs and wall off Cape Eleuthera. Even though our small team s Bahamian divemaster Neal Watson shot 5 or 6 every dive, we would see more on the next dive. On the shallow patch reefs of Eleuthera Sound, the research team took a more methological approach, tagging the fish to measure growth (they grow about 20 cm per year, they ve found) and finding that individuals can stake out particular areas of the reef for long periods of time. Lad Atkins organization R.E.E.F. helps organize Lionfish hunting derbies in the Abacos and Florida Keys, but admits that it is a bit of a lost cause. The tropical Atlantic and Caribbean is such a huge area, and the lionfish such a hardy animal, so eradication seems impossible. Hunting the fish with spearguns seems more an opportunity for sport than it does a rational attempt to protect the reef s biodiversity. Meanwhile other underwater enthusiasts are turning to more wacky solutions. In Honduras, there is an effort to try to train sharks to eat lionfish. In the Caymans, they are trying to train grouper to do the job. A more likely scenario is to try to convince humans to eat them. Once the venomous spines are cut off (you don t want to eat them), and the fish is filleted, there is delicious white meat on the fish. They may become as plentiful as cod once were, 9
and since we ve managed to destroy that fishery, perhaps we can turn to lionfish. They aren t easy to catch except by using the inefficient spearfishing method, but when you do, there are lots of recipes available to help you fry them up. In fact, R.E.E.F S Lionfish Cookbook is solely dedicated to suggesting ways of cooking and consuming this new invasive. Is this to be the future of the lionfish story? Can the environmental pollution of the Caribbean become a new foodstuff that replaces the dwindling harvest of other fish we have rapaciously removed from the sea? Neither people, groupers nor sharks seem very interested so far, but hey, stranger things have happened. 10