LIONFISH: FURTHER RESEARCH INTO THE CARIBBEAN POPULATION EXPLOSION


LIONFISH – MARMITE DENIZENS OF THE OCEAN

A short time ago I posted in some detail about the poisonous LIONFISH. I included material about the rapid increase of this Pacific species in Caribbean and Floridian waters following accidental / deliberate releases in recent years. I also included videos from Grand Bahama scuba-expert FRED RIGER to balance the anti-lionfish orthodoxy, showing that the fish in fact do some good on the reefs. The post provoked a few comments, and had a surprising number of hits. Here is some further research courtesy of the excellent SEA MONSTER which adds a dimension to the debate and concludes with a very good point… Incidentally, in a recent morning snorkelling at Fowl Cay Marine Preserve, Abaco, I did not encounter a single one of these creatures (Mrs RH was unluckily stung by a jellyfish, though…). But I guess the Preserve is well policed against such intrusive species, which are otherwise found in large numbers in the area.

Why are lionfish populations exploding across the Caribbean?

Author: John Bruno on June 6, 2012

Lionfish are an exotic fish now found throughout the Greater Caribbean and eastern Atlantic that have become incredibly abundant on many reefs, especially in the Bahamas and off North Carolina. Lionfish are piscivores (fish that eat other fish) and were introduced from the Indo-Pacific by the aquarium trade in the late 1990s off Florida. Mostly likely, someone got tired of their fish and released them purposefully.

One hypothesis explaining their great success is the absence of natural enemies; predators, parasites and competitors.  This is probably compounded by the fact that few Caribbean reefs have any predators left that could eat them (thanks to overfishing).

Another – and I think much more likely explanation – is because there is so much to eat in the Caribbean! Not because there are more fish, but because it is so much easier to catch them. Unlike fish in the Indo-Pacific, native Caribbean fishes do not appear to recognize lionfish as a potential threat.  So the lionfish gobble them up, grow faster, make more babies, spread to new islands, etc.

Case in point: My lab group was working in Belize last week on the lionfish invasion. One of the things we were doing was collecting the otoliths and gonads from lionfish that we speared on a number of reefs to compare their fitness across the Caribbean (e.g., on reefs with and without native predators, etc).  We also looked at stomach contents and many of them had parrotfishes in their tummies or still in their throats!  The photo above is of the eggs from one lionfish we caught near Glovers Reef Atoll and the partial contents of it’s stomach (a juvenile striped parrotfish)!

Lionfish appear to be little more than machines that convert parrotfishes to baby lionfishes. Which is pretty much the purpose of all animals (consuming others and transforming them into your own genotype and species).  But jeez, couldn’t those aquarium hobbyists have released a herbivore that could be converting macroalgae to fish biomass? That would have been much more useful.

LIONFISH: FACTS, VENOM & CRISIS CONTROL IN THE BAHAMAS – & A COUNTER-VIEW


LIONFISH: UNINVITED GUESTS IN THE BAHAMAS

I recently put some lionfish details and images on my MARINE LIFE page. I wrote: “…their existence and rapid increase in the waters of the Bahamas is a cause of great concern, and they are keenly hunted. Last year’s inaugural Lionfish Derby on Green Turtle Cay brought in more than 1400 of these creatures in the day, ranging in size from  a 57mm juvenile to a 349mm fish. Here, from THE ABACO SCIENTIST is where in the world the 2 species of Lionfish ought by rights to be. Well away from the Caribbean, that’s where!

 Photo credit: Brigitte Carey of Tilloo Cay

Two great lionfish photos from GRAND BAHAMA SCUBA  (thanks to Fred & Melinda Riger )

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LIONFISH Pterois

1o UNCOMFORTABLE LIONFISH FACTS

  • A genus of  spiny venomous fish indigenous to the Indo-Pacific area, of which there are 9 species
  • In the mid 1990s 2 species were introduced to the US Atlantic coast and Caribbean (see below)
  • Unaccountably popular as aquarium fish; cooked and eaten by people (though not by me)
    For recipes see LIONFISH HUNTER
  • An adult can weigh 1/2 kilo and may live up to 15 years
  • They have ‘complex courtship and mating behaviour’, presumably to avoid each other’s spines
  • Females release two egg cluster bombs every month containing up to fifteen thousand eggs…
  • Lionfish prey voraciously on small fish, invertebrates and molluscs which they gooble up in one gulp
  • They have bilateral swim-bladder muscles to alter their centre of gravity to attack their prey better
  • Apart from a tendency to species cannibalism, they have very few predators. The spines work well…
  • Sharks are not affected by the venom, and attempts have been made to train them to feed on lionfish 

LIONFISH STINGS are painful and can take several days to resolve. Tests on frogs, clams and rabbits… well, you don’t want to hear about those. In humans the venom causes systemic symptoms ranging from nausea, vomiting, fever, breathing difficulties and dizziness to convulsions and paralysis. For the very young, the elderly, the allergic or those with immune system weakness the sting can be fatal. TREATMENT: If stung it is recommended that you remove the spine(s) if possible and immerse the wound in hot water for at least 15 minutes… and seek medical treatment as soon as possible

THE CARIBBEAN INVASION supposedly started in the mid-1990s, perhaps following hurricane damage to an aquarium in southern Florida. A few earlier sightings had been recorded, possibly the result of  deliberate aquarium releases. Two of the 9 species are involved: the red lionfish P. volitans (93%) and the common lionfish P. miles (7%). It’s a measure of their rapid breeding, habitat adaptability and near-immunity from predation that the first recorded lionfish in the Bahamas was as recent as 2004. A mere 8 years later they’ve spread throughout the region. 

POPULATION INCREASE AND CONTROL The population is increasing exponentially despite efforts at control. Their voraciousness and territorial aggression must certainly be affecting the indigenous populations of reef marine life. The problem is already extreme. It is now unlikely that lionfish can ever be eradicated. Even to confine the population to its current level would require more than a quarter of the adult population to be killed monthly. Lionfish are able to reproduce throughout the year, so there is no seasonal respite. In this conservation-minded era,  official encouragement of  organised hunting bucks the trend towards creature protection. Lionfish do have food value, if natural human reluctance to eat a venomous species can be overcome, and there are now many lionfish recipes. Whether killing lionfish for sport or for food, humans are their only effective predators. Below is an example, from Oceans Watch, of the sort of campaign that will surely become commonplace throughout the region. Time to reach for the speargun…

THE COUNTER-ARGUMENT

The above is the orthodox view, widely held throughout the region. Some will ask whether the arrival of the lionfish in the Caribbean has any positives; whether they actually make a contribution to the ecology of the area; whether there is a convincing case to put forward in favour of the species; whether there is evidence to back it up. So to redress the balance I commend these 4 short videos from the enormously experienced Grand Bahama diver Fred Riger, in which he cogently demonstrates the value of this imported species. In short, the videos reveal that the adverse effect on endemic fish populations is not merely overstated but wrong; that the spreading menace to the coral reefs of choking algal growth is actually reversed by lionfish; and that important grazing crab species are thriving as a result. 
I posted the bad lionfish stuff last night; by this morning Fred had rightly taken me to task for only giving one side of the story: “Far from being a pest, lionfish are solving a huge problem created by the mother of all invasive species HUMANS, who have over fished the ocean, wiped numerous species out of existence, killed most of the world’s coral, the very stuff we in the Bahamas live on. Targeting lionfish sets conservation efforts back thirty years or more and contributes to the decline of the coral reef”. So here are the videos giving the case in favour of lionfish, and they certainly provide a fresh perspective and plenty of food for thought…
 
“LIONFISH IMPACT: THEY ARE NOT SO EVIL AFTER ALL”

5 CREATURES ON ABACO THAT YOU MAY WISH TO AVOID…


 has published an article entitled “15 cute animals that will cause you horrible harm”. For some of these, the word “cute” may be overstating the case. For others, the risks to humans appear to be very remote. A few are nominated despite being the most surprising and least likely harm-bringers (“KITTENS” – don’t ask).

What is undeniable is that 5 of the 15 may be encountered on or close to Abaco… Fortunately staying on dry land is a sure way to avoid them all – they all live underwater. With due credit to BRAINZ here are the Fearsome Five with his trenchant commentary, except for the last which I have censored for present purposes owing to its graphic adult content and anti-cetacean tendencies… 

1. PUFFER FISH “Puffer fish are hilarious and adorable just on general principle. It’s hard see one inflated, and refrain from uncontrollable giggling at it’s cartoonish defense mechanism. But puffer fish don’t just rely on their inflatable belly as a way of dissuading predators, they’re also packed with the deadly neurotoxin tetrodotoxin. Of course, they’re renowned as a delicacy just for this reason. Apparently, when prepared correctly, the minute traces of the toxin give you tingly lips and light-headedness. However, if the sushi chef doesn’t prepare it properly, you’re going to have a rather nasty death. See, tetrodotoxin is a muscle paralyzer, with no known cure. So if you overdose, your muscles no longer move, including your diaphragm. You become paralyzed, and unable to breath, slowly asphyxiating under the weight of your own chest

MORE ON PUFFER FISH SHARPNOSE & CHECKERED, IMAGES & 10 FACTS

2. LIONFISH “Lionfish aren’t so much cute as stunningly beautiful. They’re covered with majestic spines, which float elegantly along with them, as they swim around the ocean, eating their prey whole. So, what’s the problem with this stunning fish, and why wouldn’t you want one in your aquarium? Well, remember the rule of thumb when dealing with any animal: if it’s brightly colored, it’s poisonous. The Lion Fish’s spines are coated with a painful venom, which it will happily spear you with if you piss it off. While this venom won’t kill you, it will cause extreme pain, vomiting and difficulty breathing. Now imagine that happening while you’re scuba diving. Sounds pleasant, doesn’t it?”

MORE ON LIONFISH FACTS, VENOM &  CRISIS CONTROL and  POPULATION EXPLOSION RESEARCH

3. CONE SHELLS “Cone Snails are small aquatic snails that litter the oceans of the world. They have intricately patterned and eye-catching shells, which are exactly the sort of thing little kids like to pick up and eyeball when on the beach, which is when they strike. They have a thing called a “radular tooth” which is like a fleshy ribbon coated with tiny teeth, which are linked to a poison gland. It launches this harpoon of pain out of its mouth at any threat, including you. Now, a small snail will give you a sting like a bee or wasp, enough to hurt but not a major problem. The bigger ones? They shoot with enough force to penetrate gloves. You might not feel the symptoms for days, but when they kick in, you get pain, swelling, numbness, tingling, muscle paralysis, changes in vision, and eventually respiratory failure leading to death. What is with sea life suffocating you? Dang!”

MORE ON CONE SHELLS CONE SHELLS

NOV 13 ADDITION Capt Rick Guest adds to this by way of comment: “Hi RH ! At least for right now there is only one species of Cone shell in the Atlantic known to be a fish-eater and therefore potentially fatal to humans; Conus ermineus. It is one of the largest Atlantic cone species. I published a paper on this species in “The Veliger”, California Malacozoological Society, vol 19, Oct 1, 1976, if you want to bother searching for it. I observed this species spearing and swallowing sizable fish whole. Also, the Cones don’t have a radula ribbon. Their radular “teeth” are shaped like Capt Ahab’s harpoon, it’s hollow and is attached to the venom gland by an almost hair-thin tube. It is then forcibly ejected from the proboscis into the fish. A larger fish’s brief struggle will usually break the connection, but the venom works extremely fast, and the prey doesn’t go far. It is quickly located,seemingly by olfactory perception, and swallowed whole. There are now videos of this out there. Definitely look ‘em up!”

4. STINGRAYS “Stingrays are generally completely fine with humans. If disturbed, they’ll generally just run for it, but sometimes are happy to hang around and play. While shy by nature, they can become accustomed to human contact, and will let you play with them. Hell, many aquariums have touch tanks with rays in them, where you’re free to stroke the fish. The only problem is what happens when you step on them. If you disturb them in almost any other way, they’ll just dash away, but if you step on one while it’s hidden in the sand, there’s a fairly good chance you’ll get a stinger jabbed through you. For most people, this hits their leg, and the stinger remains after the ray swims off, like the lower half of a bee. In addition to being impaled, the sting also injects a hefty dose of poison, which leads to horrible pain, swelling and cramps. Again, not something you want to happen while you’re underwater. And sometimes, just sometimes, it’ll be fatal. Like when Steve Irwin—the Crocodile Hunter—got stabbed through the heart by one, dying soon after.”

MORE ON STINGRAYS SOUTHERN STINGRAYS and YELLOW STINGRAYS

5. DOLPHINS Oh, dolphins, lazy stoners of the sea. They just spend all their time floating around, eating fish, doing flips, and generally living the good life. Yeah, dolphins, they’re awesome. After all, who doesn’t love Flipper? Except, it turns out Dolphins are…” [tremendously detailed allegations follow. The general tenor is that these gentle creatures are apt to be overgenerous  with their sexual attentions, to the extent that when excited… well, they are large, powerful and agile, and they may try to do that thing that dogs do to human legs, only more attentively, to a diver. That’ll do as a summary. Oh, use your imagination]

MORE ON DOLPHINS  HERE and HERE

ONE MORE ABACO SPECIES TO STEER WELL CLEAR OF SPIDER (PEPSIS) WASPS Spider or Pepsis Wasp; Tarantula Hawk