By: Joshua Durham
Over the past thirty years, an invasive species colloquially known as the lionfish has infested coasts across the Gulf of Mexico. Originally native to the Red Sea and Indo-Pacific region, several varieties of this species now populate the coastal waters of Florida and the Caribbean. Though still under review, evidence points to the pet trade as a primary cause of their growing population, as well as changes in the North Atlantic Current transporting clusters of fish. Lionfish, unfortunately, are disrupting ecosystems and may be an example of what economists call an “externality”—an often unintended side effect of market transactions.
While the precise reason for the lionfish’s appearance in Florida is still unknown, scientists and fishers alike have witnessed damage to local fauna. For people living in these areas, the most significant threats posed by this species are to regional ecological stability, from a rapid consumption of local fish populations to a sedentary lifestyle on reefs that drives away caretakers like parrotfish. Several private venues exist to combat this growth: derbies, targeting, and traps. These tactics to manage the lionfish population are still in their early stages of evaluation, but these fish continue to damage tourism, native wildlife, and other populations on the coasts.
Two species in particular threaten local biodiversity and tourism. Yet there are at least 16 different species sighted in Florida’s coastal waters. Their bright coloration and relatively slow movement allow them to be nearly untraceable on large bodies of coral. Disguising themselves on reef heads, their spines produce a neuromuscular toxin that allows them to immobilize their prey, which causes painful local paralysis in humans. While these inherent gifts make them renowned predators, the true threat comes from their rapid reproduction rate.
Females sexually mature within one year and lay clutches of eggs on average every four days. One clutch contains 30,000 eggs with an average development of twenty-six days. This period is shorter than in their native locales in the Pacific. The species also has a lifespan of up to fifteen years: an unfortunate reality many afflicted regions have come to realize. In other words, one small colony of lionfish could quickly cover an entire reef head within two months.
This uncontrolled growth is coupled with the fact that few natural predators can combat the species, as possible reef predators have either been significantly reduced in numbers or do not exist within the region any longer. Lionfish are now the primary major predator in many locations on the coast, consuming all types of native wildlife. Their presence has also prevented parrotfish and wrasse from properly maintaining reefs, and their explosive growth has led to lionfish cannibalism.
Overpopulation with the lionfish is worsening. Areas to the north such as the Carolinas and areas in the south like Venezuela show evidence of populations and their repeated attacks on local wildlife. The invasion continues to grow at a rate that requires direct action soon for fear of no reefs left to conserve.
What role can the private sector play in managing the lionfish invasion? This question will be explored in Part 2 and Part 3 of this series.