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
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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
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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.
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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.
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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.
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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.
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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
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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.
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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,
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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.
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