Nobody believed scuba instructor Jose Pelaez, when he claimed in March 2009 to have seen a lionfish on one of his dives off the coast of the Tayrona National Park on Colombia’s Caribbean coast. The fish, a native of the Indo-Pacific, had already invaded reefs along the whole of the eastern side of Central America and a stretch of the U.S. East Coast ranging from Florida to Virginia. But few thought it could have spread as far south as Colombia so quickly.
A few days later a diver managed to photograph one of the colorful creatures. All doubt was removed when Pelaez brought the carcass of a lionfish – which he had speared with a harpoon – back to shore.
By August 2010, fishermen were regularly dragging up lionfish in their nets. Swimmers and snorkelers would frequently report sightings of the pest, while divers would spot up to ten specimens per dive.
Unlike most well-known marine predators, lionfish are small, only growing to a maximum of 21 inches. They sport reddish brown stripes over a white translucent body, but they can change their colour to blend into their environment – much like chameleons. On their sides and backs, their fins tail off into long flimsy spines. It is because of their colorful appearance that these fish are so sought-after by the aquarium trade. But why then did Pelaez’s sighting of an animal, which many people consider to be beautiful, raise such alarm?
Marcela Grijalba, marine biologist at the GIPECA, a marine research institute of the Jorge Tadeo Lozano University, explains that the lionfish represents a danger on two fronts.
Firstly, its venomous dorsal fins can present a risk to fishermen and divers. “The venom is so strong that they can even sting through a wetsuit,” she warns. “A sting usually causes excruciating pain and, in the Indo-Pacific, there have even been reports of the venom being fatal.”
Secondly, the fish’s voracious appetite is a serious threat to marine ecosystems. “A lionfish can eat between ten and twelve juvenile fish a night,” Grijalba explains. “Its stomach can expand to up to thirty times its size.” Because the lionfish is a species alien to the Caribbean, local reef fish do not know how to react to it. “They are easy prey. They don’t identify it as a predator and therefore don’t know that they should try to avoid it.” The lionfish’s feeding patterns can lead to a reduction in biodiversity and a depletion of fish stocks. A possible consequence of this is unemployment in coastal communities, as fishermen lose their jobs, Grijalba predicts.
A conversation with a group of fishermen in Taganga, a harbor town on the edge of Tayrona appears to confirm Grijalba’s assessment. “We only catch between 30 and 40% of the fish we used to catch before the arrival of the lionfish,” one fisherman complains as he looks out to sea. The rest of his crew nod in agreement.
Yet how did this fish, which is originally from the Indo-Pacific, reach Tayrona’s reefs? Grijalba explains that there are two hypotheses. The first is that aquarium owners in Florida freed the fish into the Atlantic. Many biologists, Grijalba included, identify Hurricane Andrew’s destruction of a seafront aquarium in 1992, which caused six specimens to be released into Florida’s Biscayne Bay, as a key contribution to the species’ propagation. According to the second theory, lionfish were dumped into the sea near the Panama canal by large trans-ocean cargo ships, when they emptied ballast water which they had taken on off the shores of Asia.
Their arrival is only part of the story. A combination of factors has led to an explosion in their numbers. Unlike their brothers in the Pacific, they have no predators, allowing them to feed and reproduce in peace. In addition, it helps that they are extremely fertile. “They reach sexual maturity when they are only one year-old and they live until they are fifteen,” Grijalba explains. A female spawns up to two million unfertilized eggs a year. Once the eggs have been fertilized and have hatched into larvae, they are dispersed by large currents such as the Gulf Stream and the Caribbean current. Grijalba refers to data provided by the U.S.National Oceanic and Atmospheric Administration (NOAA) to demonstrate that the pests’ invasion of the Atlantic took place at lightning speed. In 2000, lionfish sightings were restricted to a few sites off the East Coast of the U.S. But by 2009, specimens were being spotted as far south as Venezuela and as far north as New York.
The Colombian Environment Ministry was quick to react. In a resolution issued in February 2010, it classified the lionfish as an “invasive species”. It took steps to inform divers and residents of the coast of the areas where the species could be found, to ban the keeping of lionfish as pets and to warn tourists of the presence and threat represented by the pest.
But others took a more hands-on approach. Within days of Pelaez’s first sighting, Jose Felipe Mesa, scuba diver and co-founder of the Prosperar Foundation for sustainable development, was leading diving expeditions to cull lionfish with small foot-long harpoons in Tayrona’s waters. He says he has become so used to the practice that, when he saw a lionfish in an aquarium on a visit to Medellin‘s Parque Explora, he instinctively reached for his hip – where he would carry his harpoon on a dive. On August 15, he organized a large-scale lionfish hunt off the shores of Tayrona. Seventy-one divers from around Colombia and four diving schools participated in the event, in which 132 lionfish were killed or captured. “I hope that events such as this will encourage more local diving schools to follow suit and organize their own hunts,” Mesa says.
What does Grijalba make of the effectiveness of such lionfish hunting? “I think it can have a mitigating effect,” she says, “but it is not the solution to the problem.” Is it possible that marine ecosystems themselves find a way to deal with the plague? “It is possible the fish community matures to the point that predators of the lionfish appear. However, this could take a number of years or even decades. By the time this occurs, it could even be too late and fish populations could be drastically reduced, because, on top of lionfish, there is the threat posed by overfishing.”
So is she optimistic or pessimistic about the possibility of resolving the lionfish crisis? “Frankly I am pessimistic because, in my opinion, the environmental authorities have a very passive attitude to developing and financing viable and concrete strategies.”
A bleak outlook. Nevertheless, Grijalba’s last answer suggests that solutions to the crisis may be found with the right research and investment on the part of the authorities. Optimists will conclude that a correctly organized human response could succeed in containing the pest. If this is so, the authorities must hurry. Tonight alone, off Tayrona’s shores, thousands of fish will disappear down the gullet of a creature they weren’t even able to recognize.
The photos used in this article are accredited to the Vida Marina Diving School, the Jorge Tadeo Lozano University and Santa Marta aquarium.