The Central Caribbean Marine Institute’s (CCMI) article on the Lionfish problem in the Caribbean and the steps being taken by the Cayman Islands

The RAP Sheet:

– In the Caribbean, a single female lionfish can spawn over 2 million eggs per year

-Lionfish have the potential to reproduce every 4 days, throughout the year

– Lionfish eggs are held together in a gelatinous mass and are dispersed at the ocean’s surface by currents, where their larval duration is about 26 days

– Lionfish become sexually mature in less than 1-year

– Lionfish may live longer than 15 years, reaching sizes exceeding 47cm (~20 in.)

– Lionfish inhabit all marine habitat types and depths (shoreline to over 600’)

– Lionfish possess venomous spines capable of deterring predators and inflicting serious stings and reactions in humans

-Lionfish are indiscriminate predators with voracious appetites

Two visually identical species of lionfish were introduced into the Atlantic via the U.S. aquarium trade in 1990’s and have been documented from Massachusetts on the U.S. East Coast to South America, including the Gulf of Mexico, Bermuda and throughout the Bahamas.

Other Caribbean nations such as Turks and Caicos, Cuba and the Cayman Islands are also affected. Their expansion has been extremely rapid and exponential in scope and follows the patterns of current movements around the U.S. East Coast and Western Atlantic on into the Caribbean.

If you ask a marine biologist…

why lionfish are such successful invaders they will respond with a laundry list of ecological characteristics that combine to paint a nasty picture of an even nastier fish.

Among these characteristics you will always hear ‘lionfish lack natural predators’.

Well, on Little Cayman we beg to differ.

The resident dive masters qualify as predators in every sense of the word AND they hunt in packs…

The Little Cayman dive resorts, including the Southern Cross Club, Little Cayman Beach Resort, Pirates Point Resort, Conch Club Divers and Paradise Villas, have all made a serious commitment to the reduction of the lionfish population in the world famous Bloody Bay Marine Park. The effort is being backed by all of the resorts which have teamed together for weekly lionfish hunts. Each week a different resort donates boat hours and all four resorts allow staff to attend.

The Cayman Islands Government has recognized the importance of this environmental predicament, and through the Department of Environment, have begun licensing the local dive master population in an effort to cull the Lionfish population.

Until recently, local Cayman laws have prohibited the culling or removal of any fish inside a marine park, and the use of spears has been illegal since the establishment of the marine parks in an effort to conserve the environment. Thankfully, through insight and education, the laws have been adapted to allow for the effective culling of this invasive species.

The Lionfish culls on Little Cayman are organized by the Central Caribbean Marine Institute (CCMI), who are using this unique opportunity to collect data on the effectiveness of lionfish removal efforts. Data of this type is desperately needed to build accurate modelsand plan for the future of lionfish population management.

Researchers on staff CCMI are analyzing stomach contents, reproductive maturity, age and growth of the lionfish. Otoliths are the tool used to determine age, and in a sense are small stones that help to orient and position the fish in the water column. Each year they lay down rings made of calcium carbonate and by sectioning these tiny structures and counting the number of rings present, researchers can determine the age of that particular fish.

While we currently do not have age and growth information for this area available, similar data collected from other areas in the Caribbean suggests that this invasive population of lionfish is growing larger and faster than their Pacific cousins. We hope that once the data from Little Cayman is analyzed, it will provide scientists with more accurate information that will in turn help us to make better management decisions.

In addition to the lionfish culls, CCMI also hosts appreciation barbeques for the participating dive masters using the Lionfish caught on the hunts. Lionfish meat is very palatable which offers extra incentive to continue the push to collect more fish.

All of the dive resorts and CCMI recognize the importance of controlling the local lionfish population, even if operating costs increase due to extra boat time and man hours. The weekly culls have become so popular that space on the dive boat has become a premium with a priceless look on the latecomer’s faces as they loose their spot to an increasing waiting list. With single catches reaching triple figures and with the added excitement of the hunt as well as the camaraderie around the bar afterwards, it’s easy to understand why the culls are so popular amongst the dive masters.

With the Little Cayman community this invested, they have an excellent opportunity to set the standard for the rest of the Caribbean with regard to controlling the lionfish. Furthermore, besides the obvious positive impact on the environment, Scientists and Reef Managers have a better opportunity to understand whether culling over a controlled area for an extended period of time can be successful, and possibly how much effort it will take to reduce the impact of this invasion. These results may provide the impetus for a more regional effort in the future.

The Central Caribbean Marine Institute (CCMI) is an international non-profit organization with over 10 years of environmental leadership in the Cayman Islands. Since its first years, CCMI has proven a valuable asset to the effort of understanding the factors that lead to coral reef sustainability and the factors that are stressing this ecosystem. The success in ecosystem sustainability relies on long-term data collection and analysis, excellence in reporting and communicating results, and by inspiring environmental stewardship through education and outreach programs such as this Lionfish culling program.

With the Cayman Islands as the focal point for all activities, the research and the field station of the Central Caribbean Marine Institute offers a unique and important reference for coral reef studies. Since opening in 2006, the field station, the Little Cayman Research Centre has attracted over 50 scientists from 7 countries.

The CCMI “Dollar a Dive” initiative allows visiting divers to donate funds which are used directly by the Little Cayman Research Centre to fund activities like the Lionfish culling initiative.

Lionfish are generalist, indiscriminate carnivores that consume in excess of 56 species of fish and many invertebrate species, with prey in excess of half the lionfish’s body size.

Scientists have recorded up to 22 fish in a single lionfish stomach as these opportunistic predators feed a high metabolism, spurring their exceptional reproductive rate.

The aggressive feeding behavior of the lionfish may impact multiple trophic levels by reducing the abundance of other herbivorous fishes that keep seaweeds and macroalgae from overgrowing corals.

The Little Cayman dive masters have been training the Nassau Groupers to eat and also hunt the Lionfish with surprising success. Little Cayman has the largest spawning site of Nassau Groupers in the Cayman Islands.

These groupers have been witnessed hunting the Lionfish in the Bloody Bay Marine Park indicating that this important and threatened grouper species may be a critical part of nature’s own solution over time.

The overwhelming consensus among scientists is that lionfish eradication will be impossible due to the geographical extent of the invasion. However, efforts with a high level of commitment such as the one on Little Cayman can make a large difference in localized areas such as the Bloody Bay Marine Park.

The outpouring of support and community action in Little Cayman should be used as an example for other communities wishing to make a dent in their local batch of venomous invaders.