News: Lionfish Invasion in the Atlantic

Lionfish are an incredibly unique species, known for their striped appearance and spiky fins. These saltwater fish are popular among experienced marine hobbyists and they come in several sizes and varieties. These fish are native to the Indo-Pacific but they have recently begun to infiltrate the Atlantic Ocean. In fact, environmentalists are very concerned with the growing population of lionfish around Bermuda. Lionfish are top-level predators and they have the capacity to wipe out 90% of a reef – this makes them a major threat to Atlantic habitats. Read more to learn about the lionfish and the potential problems caused by their spread.

Facts About Lionfish

Lionfish belong to the genus Pterois and they are typically found throughout the Indo-Pacific. These fish are known for their banded pattern exhibiting colors like black, red, white and orange. The most identifiable characteristic these fish have, however, is their spiked fins. There are ten different species of lionfish and they range in size from 2 inches (5 cm) to 18 inches (45 cm) in length. The lionfish is a dangerous predator because their spikes contain a deadly venom. Though these spikes are typically used for defense, they can be deadly to unsuspecting prey or would-be predators. A lionfish sting is extremely painful to humans and it can cause nausea and breathing difficulties. It is, however, rarely fatal.

Unlike some marine species, lionfish are capable of reproducing very quickly. These fish become sexually mature at 1 year old and they can produce 30,000 to 40,000 eggs every few days. Lionfish have a lifespan between 5 and 15 years and they have been known to exhibit complex mating behaviors. The lionfish will sometimes cannibalism smaller lionfish but, for the most part, this species has few natural predators. Moray eels, large groupers and bluespotted cornetfish have been seen to prey upon lionfish but it is unknown how common these instances are. It is also though that sharks are also able to consume the fish without experiencing ill effects from the venom. Not only do they have few natural predators, but lionfish are infrequently affected by parasites.

Lionfish Invasion

Whereas once they were limited to the Indo-Pacific region, these fish are now found throughout the Amazon, the Caribbean and even off the coast of the U.S. Because the lionfish is not native to the Atlantic, it stands to reason that the species was at some point introduced. Though the exact cause of the lionfish invasion is unknown, it is likely that the aquarium trade played a role. It has been theorized that the growing population of lionfish in the Atlantic may have stemmed from the release of less than 10 female lionfish by pet owners in the southern U.S. The two species most prevalent in the invasion are P. volitans (the red lionfish) and P. miles (the common lionfish). Coincidentally, the common lionfish is the most popular of the ten in the aquarium trade.

Control Efforts

According to the National Oceanic and Atmospheric Administration, nothing can be done to control the invasive population – this means that their numbers will continue to grow. The rapid spread of the species is partly due to its prolific breeding habits, but largely due to the fact that the species has few natural enemies. This can be particularly devastating in the Atlantic Ocean because Atlantic species are not familiar with the lionfish and do not know to avoid it. The effects of this invasion on the commercial fishing industry and native populations has not yet been determined, but scientists are carefully studying the impact of invasive species on marine ecosystems.

Though unlikely to have a significant effect in the long run, conservation groups have begun to take steps to control the population of lionfish. The Environment Education Foundation, for example, holds annual “lionfish derbies”, awarding a cash prize to the diving team that catches the most lionfish. In Florida, the Florida Keys National Marine Sanctuary has even begun to issue licenses for divers to kill lionfish inside the sanctuary. The NOAA has also started a campaign to encourage the eating of lionfish. Though the spines are venomous, when the fish is filleted properly it is entirely safe to eat.

As the lionfish population in the Atlantic continues to grow, there is little hope for control or eradication. A study conducted in 2010 using population modeling suggested that, in order to maintain even the current population density, 27% of the lionfish population would have to be killed each and every month. Because this is unlikely to happen, we can only watch and wait to see the long-term effects of this invasion.