Tuesday, September 20, 2011
The Taming of the Lionfish
The lionfish is a hot item in SCUBA current events. Though beautiful to observe, the lionfish has infiltrated a marine ecosystem it does not belong to, causing devastating effects to coral reef systems in the Atlantic along the eastern cost of the US and the Caribbean. Local government and environmental agencies are beseeching SCUBA divers to actively hunt and kill the lionfish, which as it turns out, is a rather tasty fish that can be prepared in a variety of ways. So what’s the big deal about lionfish?
Lionfish is the common name for a genus of fish called Pterois, which features about 15 different species. There are 2 species which have invaded the Atlantic and Caribbean: P. volitans and P. miles. Originally from the waters of the Indo-Pacific region, lionfish have been a very popular choice for aquarium enthusiasts in the US for quite some time. There are several theories as to how the lionfish came to be in the local environment. One such theory is that the invasion was facilitated through the destruction of a southern Florida aquarium during Hurricane Andrew in 1992. Another tells of lionfish being accidentally released following the hurricane, and yet another proposes aquarium owners were deliberately releasing them into the sea, unsatisfied with the way the lionfish performed in the aquarium. Still others claim to have spotted the lionfish on local reefs even before Hurricane Andrew.
The lionfish has been able to reproduce at such profuse levels due to certain crucial factors:
Lionfish have no natural predators on the reefs of the Atlantic and Caribbean. Any creature that sits at the top of the food chain, unchecked by nature, will enjoy the privilege of populating an area with its own species. But this can have disastrous implications for the area as the system becomes more imbalanced.
Lionfish have a voracious, unbiased appetite for reef species. The lionfish is an indiscriminate predator, feeding on invertebrates, small fish, mollusks, and juvenile species in large amounts. Up to 6 species of fish have been found in a lionfish stomach at one time. They are aggressive and skilled hunters, using specialized characteristics of their bodies to stalk and overtake prey, which they do in one giant swallow.
Lionfish spawn at a highly accelerated rate. The female lionfish releases clusters of 2,000 to 15,000 eggs at one time, which are then fertilized by the male, and hatch 36 hours later. Within 3 days they are competent swimmers, and capable of capturing and consuming small prey. Within 20 – 40 days, the lionfish begins its metamorphosis to adult. Lionfish females can repeat this process on a monthly basis with no set breeding season, and the typical lionfish lives between 5 and 15 years.
Lionfish are hostile and venomous. The lionfish is covered in long, venomous spines that serve as a deterrent to predators in its natural environment, and are incorporated into the capture of some prey. The effect of the venom on prey is fatal, whereas the effect on humans is painful, and can bring about symptoms of nausea and fever, but is very rarely fatal. They are extremely aggressive toward other reef species, either chasing them away from the reef or consuming them in a territorial play.
According to research, lionfish are responsible for wiping out up to 80% of reef species in the Atlantic and Caribbean. A few studies have shown the Caribbean grouper to be a predator of the lionfish, but due to overfishing, there are not enough grouper to contain the wild spread of lionfish populations. That’s where SCUBA divers, snorkelers, and anglers come in.
If you live in these areas or will be traveling to one soon, check into local programs dedicated to controlling lionfish populations. Although complete eradication is deemed unrealistic, people with SCUBA training can be of immense assistance in keeping reef ecosystems from being ravaged by this most unwelcome visitor.
Photos via NOAA’s National Ocean Service, mtarlock, Serge Melki
thanks to Book Your Dive and Creedence