GAINESVILLE — When invasive lionfish came on the scene in the Gulf of Mexico, one proposed solution came with them: Control their populations and impacts by commercially harvesting them. In other words, “eat them to beat them.”
But large-scale lionfish fisheries have yet to establish in the region. Despite lionfish being tasty and consumers having an appetite for them, they’re rarely sold in restaurants and supermarkets.
University of Florida researchers wanted to know why — and what would need to change to make this kind of fishery viable.
The UF team has just published a study showing that, under current economic conditions, the profit margins for commercially harvested lionfish are relatively low. This may explain why many commercial fishers aren’t targeting the species.
In the study, the researchers developed the first bioeconomic model for lionfish in the Gulf of Mexico. A bioeconomic model combines what is known about a species’ biology — such as how fast it reproduces and the size of its population — and the economic factors that motivate fishing efforts.
“The bioeconomic models produced in the study examine ecological-economic feedbacks. We used them to estimate parameters for understanding lionfish population dynamics and harvest, and they allowed us to explore how economic strategies could support invasive species control,” said Holden Harris, who worked on the study while a post-doctoral researcher at the UF/IFAS Nature Coast Biological Station and is the study’s first author.
“Our models show that the current harvest of lionfish is below what would be needed to overfish the lionfish population. This means that current harvest efforts may not be reducing lionfish densities to low-enough levels for mitigating their impacts on native reef species,” said Sherry Larkin, the study’s senior author, a professor in the UF/IFAS food and resource economics department, and the director of Florida Sea Grant. “We also note that reducing lionfish stocks over time through commercial fishing would make the fishery less economically sustainable.”
Over the last few decades, invasive lionfish have spread through the western Atlantic Ocean, Caribbean Sea and the Gulf of Mexico. Recently, lionfish have also invaded the Mediterranean Sea via the Suez Canal. Like other invasive species, they are a problem for native ecosystems because they have few predators, produce lots of offspring and prey on native species.
That means humans are the lionfish’s primary predator. However, current lionfish removal methods are time-consuming, so additional incentives may be needed to encourage their harvest, according to researchers.
“Currently, spearfishing is the most effective means of catching lionfish. This entails divers using SCUBA and collecting lionfish one-by-one,” said Harris, who is now an assistant scientist at the University of Miami working in the NOAA Southeast Fisheries Science Center. “And they’re pretty small, on average weighing maybe a pound per fish. So commercial fishers need to spear a whole lot of them to make a profit. To find these high densities, fishers generally need to dive fairly deep, often past 130 feet, which requires trained and experienced divers.”
In the study, the researchers modeled how changes to supply and demand could make harvesting lionfish more economically feasible.
“To increase harvest, we can increase the price that fishers receive for lionfish or reduce the cost to fish them”, Harris said. “If new harvest technologies could be developed, such as lionfish traps, these could potentially catch more lionfish at once or at greater depths.”
Efforts to market lionfish as an ecologically friendly seafood choice have helped to raise their price to where it is now, Harris said.
“Alternatively, there are mechanisms and efforts to increase the price of lionfish”, Harris said. “For example, some artisans and companies have begun developing lionfish byproducts, for example, using their fins to make jewelry and their skin to make leather. Finally, government programs that subsidize the price of lionfish would make harvesting them more attractive.”