The porcupines of the sea are thriving
From a distance, the lionfish looks majestic, beautiful even. It has long, flowy fins and intricately placed cream and reddish-brown vertical stripes. Don’t get too close though — their flowy spines are venomous and can cause an excruciatingly painful sting.
These invasive fish are rapidly increasing throughout the coasts of Florida and the Caribbean. According to the Florida Fish and Wildlife Conservation Commission, lionfish can spawn up to every four days in warmer climates. Female lionfish release about 30,000 eggs per spawn, and produce about 2 million eggs per year; however, not all of those eggs make it to adulthood.
Many scientists believe that warming oceanic temperatures are directly related to the increase in these ubiquitous fish.
“Lionfish in the Gulf of Mexico have the potential to reproduce every two and a half days, about 11 months out of the year, with spawning activity linked to water temperature,” environmental science graduate student, Emma DeRoy, said.
Miami Shark Research and Conservation Program intern, Patricia Albano, uses the word “epidemic” to describe the lionfish outbreak. “Increased temperatures set the perfect stage for an invasion to thrive,” Albano said.
Warmer conditions allow lionfish to spend less time in pelagic larval stages, meaning they’re able to mature faster and reproduce sooner.
Another issue with lionfish is how other sea life is responding to their presence. According to the National Ocean and Atmospheric Administration, (or NOAA), lionfish have few natural predators, and their 18 venomous spines contain neurotoxins, which kill off native reef fish by releasing toxins into the reef systems.
Areas like the Atlantic coast of Florida and the Gulf of Mexico are perfect for lionfish because of their warm waters and coral reefs. They’re thriving in these waters, while simultaneously stripping the oceans of native fish and coral sites.
Lionfish could potentially have detrimental effects on marine ecosystems and the economy.
“They eat indiscriminately and they eat a lot (their stomachs can expand about 30 times their original size). So, given their high consumption rates, they have the ability to extirpate species,” DeRoy said. “If lionfish consume large numbers of juvenile snappers and groupers (both recreationally and commercially important species in Florida), the economic implications can be quite large.”
As of right now, their only inhibitor is cooler oceanic temperatures. At about 10 degrees Celsius (60 degrees Fahrenheit), the lionfish begin to stop feeding. At about 16 degrees Celsius (50 degrees Fahrenheit), they start to die off, according to a NOAA marine ecology research team (Kimball et al.).
This is a problem because, since the oceans are warming, there is nothing stopping lionfish invasions.
Since there are no known lionfish predators, Florida Wildlife Control encourages fishermen and divers to safely remove lionfish if they are found to help control the invasions. Some organizations such as the FGCU Spearfishing Club have competitions to kill lionfish since there is no bag limit on these fish. Other lionfish anglers harvest them for food.
Scientists are trying to figure out ways to mass-kill the lionfish.
An organization called Robots in Service of the Environment (RSE), has been working on robotic technology to solve the issue of lionfish invasions. While on a diving trip in Bermuda, Colin and Erika Angel noticed the destruction to the reefs caused by lionfish, and soon came up with the idea of RSE and formed the non-profit organization.
While spearfishing lionfish has proven to be somewhat effective, there are still many limitations. The lionfish sometimes swim to waters that are too deep for divers.
“If deeper waters along the West Florida Shelf begin warming, it provides lionfish with a refuge,” Emma said. “What this means is that, while we might still spear a lot of lionfish in nearshore waters, we really aren’t targeting the fish at the source — if most of the population is hiding out in deeper waters, they can then keep reproducing and building their population in deep waters, with a subset of these individuals radiating inwards to nearshore waters.”
There are also lionfish-specific traps being set up that capture the lionfish without trapping by-catch like snapper and grouper.
The lionfish are thriving and finding new ways to continue expanding their colonies. Increasing temperatures are only helping them reproduce and overtake native species.
“In the case of lionfish, we still don’t fully understand them as an invasive species and certainly, it’s difficult to solve a problem that you don’t fully comprehend,” DeRoy said.
