Tackling the lionfish problem

Once considered exotic and beautiful, the Indo-Pacific Red Lionfish has become the bane of the Caribbean and Atlantic seas, multiplying rapidly and stripping coral reefs of its juvenile fish populations. 

In Cayman waters, the fish were first spotted in early 2008 at a dive site in Little Cayman. Since then, divers have been leading the battle to control the exploding population of these venomous creatures throughout the Cayman Islands, while local and visiting scientists have been researching the effectiveness of culling efforts. 

Initially, the weapons of choice against the invaders were nets into which the striped, spiny fish were ushered. But those proved slow and cumbersome amid the crevices into which the lionfish invariably darted once they sensed hunters were about to trap then. The Marine Conservation Law was amended to allow divers to use spears to kill lionfish underwater.  

The Department of Environment issues pole spears on behalf of the Marine Conservation to licensed cullers, who are required to attend a training course to be eligible to apply for a licensed spear. The training course also addresses how to handle lionfish, which can deliver a painful sting with its 18 dorsal and anal spines. The spines contain neurotoxins which can cause severe pain, swelling and rash in humans. 

The three-pronged spears enable divers to poke into nooks and crannies in the reef to stab and grab lionfish. Initially, all captured lionfish were handed over to the department for DNA testing. But the numbers soon proved unwieldy and now the department accepts reports from divers on where they have culled the fish and their measurements. The speared fish are now either placed quickly into collection buckets and taken back to land to be eaten or end up in the bellies of snappers and moray eels that follow divers and bite the fish off the spears. 

A burgeoning market for lionfish meat – which is white, fleshy and tasty – in the Cayman Islands means that after a hard day of lionfish hunting, divers can take the fish to a restaurant, such as Michael’s Genuine at Camana Bay or Tukka in East End, and have it cooked up. Local supermarket Foster’s Food Fair IGA sponsors weekend two-tank dive trips during which everyone on board is a lionfish culler or a spotter. Lionfish caught on those dives are de-spined and cleaned and delivered to Foster’s, which sells them at the fish counter. 

Perhaps the most regimented culling has been done on Little Cayman, where dive professionals remove as many lionfish as they can from specific sites. Their work has been subject to a study that, for the first time, measured how effective it is to target individual sites. 

The report, titled “Coping with the lionfish invasion: Can targeted removals yield beneficial effects” from the Central Caribbean Marine Institute in Little Cayman and the University of Florida, published in July, found multiple culling efforts at one site reduces the lionfish population significantly. The study effectively proved anecdotal evidence that fewer lionfish were present on sites that were regularly culled. 

In the meantime, staff and volunteers at the Central Caribbean Marine Institute’s lab in Little Cayman has been studying captured lionfish to better understand their breeding and growth rates. 

In late 2012, Cayman’s lawmakers unanimously voted to support the introduction of a $5 bounty on lionfish, with the reward money being supplied by the Environmental Protection Fund. So far, no more has been heard of this proposal. 

While the Department of Environment has worked hard to coordinate and assist with lionfish culling efforts – through culling tournaments, public awareness campaigns and sponsored dives – there has been little financial input from the government in the battle against the lionfish, despite acknowledgement during the debate among legislators last November on the bounty that lionfish posed one of the greatest risks to the Cayman’s reefs and fish populations. 

Lionfish are considered a major threat to coral reefs because they are ravenous predators that eat huge quantities of juvenile fish and crustaceans and have no natural predators. They can spawn up to three times a month and can produce as many as 30,000 eggs per spawn. They are able to begin reproducing when they are younger than one year old.

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