Lionfish: The Elegant Predator
Native to the Indian and Pacific Oceans, Lionfish (Pterois volitans) have become increasingly at home in waters throughout the Caribbean and off the Eastern seaboard of the United States. Unfortunately the influx of these venomous predators is very much to the demise of local species in these areas.
Lionfish quickly dominate the reef systems in their adopted homes and destroy local fish populations with their voracious appetite for the young of other creatures. The resultant imbalance of coral reef eco-systems is a major concern to those entrusted with both conserving marine environments and restoring them to their natural order.
It is believed that Lionfish were introduced to western Atlantic waters when a hurricane destroyed an aquarium in Florida, emptying its contents of which Lionfish were a major part, into the sea. Subsequently eggs and larvae have been dispersed via the Gulf Stream, and Lionfish have been spotted from southern Florida up to Cape Hatteras in North Carolina, while juveniles have been discovered in the Belize, the Bahamas and as far north as Bermuda. There are currently culling programs operating in Belize and the Bahamas, but the first place to introduce such a system was the island of Bermuda. I recently had the opportunity of speaking with Chris Flook, the Bermuda Lionfish Project co-ordinator, and asked him what specific damage these alien invaders cause to the environments that they overrun.
“First of all”, he said, “they are active opportunistic aggressive feeders. In their native region, they work hard for their food; other predators see them as a threat and seek to destroy them, so lionfish are programmed to eat as much as they can whenever they can because they might not eat tomorrow. The fish here in the Atlantic don’t see them as a threat (yet) and this allows the invasive Lionfish to satisfy its endless appetite freely.”
“In a study in the Bahamas” he continued, “eighty percent of the native fish disappeared off our study reefs when Lionfish appeared on them.”
Chris went on to tell me of how the presence of Lionfish causes tropic cascades. A tropic cascade is the effect of a population change of a particular species in the food change. For instance, Lionfish eat all the cleaner shrimps. When there is a lack of cleaner shrimps, other fish get sick and die, and the degeneration of the reef system continues. An amazing fact is that in every single Lionfish, in which a necropsy was performed by Chris and his team, has had fatty liver disease, a sign of overeating not normally seen in wild fish and usually reserved for farmed animals.
Fortunately the culling programs are having a measure of success in restoring the affected marine environments back to their natural states, though Chris stressed that it’s still early days and that “fish population assessments will come in time, and we will know more as the invasion unfolds. People have to be trained in handling them as well” he emphasised, “They are venomous to humans, and though fatalities are rare, they have fin spines that can produce painful puncture wounds.”
The Lionfish Project is actually considered a model for management of destructive invasive species on a global scale, and is the coordinated effort of at least six major organizations: The Bermuda Aquarium Museum and Zoo, The Bermuda Zoological Society, the Department of Environmental Protection, the National Oceanic and Atmospheric Administration, the Reef Environmental and Education Foundation (REEF) and the US Geological Survey. The goal of the project, in Chris’s words is to “Debunk the myths and get the facts out, educate and potentially manage the population so we have other fish as well as lionfish, and to try and make inshore nursery areas and dive sites lionfish free zones”
The great part of the culling programs is that governments are backing them, and issuing licenses to fishermen interested in harvesting them. Chris meanwhile is working enthusiastically to get them onto the local fish markets. “The red tape is moving and restaurants are excited”, he said. “Eat’Em to Beat’Em is our campaign slogan! They are an excellent choice for the eco-friendly fish eaters. I like to eat fish too, and I can tell you the meat is delicious!”
If you’d like to know more about the Lionfish Project, Chris was recently a keynote speaker in Marathon, Florida at a seminar on invasive species, where he was asked speak about the initiative. You can view his commentary on the seminar and the Lionfish Project in this video.