Combatting An Invasive Species: The Lionfish

Fire ants, zebra mussels, Asian carp, Burmese pythons… what do all of these species have in common? They’re abundant in certain parts of the U.S. and are outcompeting many other species in their respective habitats. What you may not know about these species is that none of them are native to the areas in the U.S. that they are taking over. Fire ants are from South America; zebra mussels and Asian carp are from Eurasia; Burmese pythons are from Southeastern Asia. All of these species have been introduced into the U.S. for various reasons and have since flourished in these environments. These are textbook examples of invasive species. Once established, they begin to outcompete and drastically endanger native species.

lionfish_infestation

Photo by Richard Carey

In the marine environment, there is one particular invasive species that is wreaking havoc on coral reef environments in the Western Atlantic: lionfish. These venomous fish were introduced into Florida waters from their native Indo-Pacific waters in the 1980s when aquarium owners decided they didn’t want them anymore. The pet trade has been the cause of the establishment of many invasive species, but lionfish are one of the worst culprits. Lionfish reproduce very quickly; a female can release two masses of up to 15,000 eggs as often as every four days. These fish also have high site fidelity, meaning once they find a habitat that is good for them, they will remain there. In some areas, the density has reached 200 adults per acre. There invasion has grown rapidly into other Southeastern U.S. states’ coasts, as well as into the Caribbean Sea. Projections indicate that lionfish will continue migrating further north and south; juveniles have recently been spotted of the coasts of some northeastern U.S. states and in both Columbia and Venezuela in South America.

Lionfish are voracious predators that will eat practically anything that fits into their mouths; one study conducted by the National Oceanic and Atmospheric Administration (NOAA) found over 40 different species of fish in their stomachs, including ecologically and economically important ones, such as grouper and yellowtail snapper. Lionfish are known to corral prey with their large, fan-like pectoral fins and then blowing water at the prey until they turn around and then promptly devoured. Lionfish eat many juvenile fish, which significantly reduces the number of native fish species, particularly ones that help feed grouper and snapper populations, as well as species that keep sea grasses and algae from overwhelming coral reefs.

The invasion of lionfish has led to some creative mitigation methods, including NOAA’s “Eat Lionfish” campaign. NOAA and others are working to encourage an appetite for lionfish in the seafood market, including hosting lionfish food fairs and seafood receptions. Don’t worry, chefs remove the venomous spines before the fish are sold to markets and restaurants. The Reef Environmental Education Foundation (REEF.org) has even released a cookbook that includes information on how to safely catch, handle and prepare lionfish recipes. The 2011 Smart Seafood Guide also encouraged the public to begin dining on this invasive species, deeming it the “safer, more sustainable” seafood product, as many popular food species are overfished and their numbers are declining.

lionfish_cookbook_coverWhile this one mitigation method will be helpful, other efforts are needed to reduce the lionfish populations. Total eradication is very unlikely, if not impossible, because lionfish have already shown that they can easily adapt to different environmental conditions, including colder temperatures and deeper depths. In February 2015, NOAA’s Office of National Marine Sanctuaries released a 3-year comprehensive plan on how to respond, control, and adapt to an active marine invasion, specifically the lionfish. You can find this document here.

REEF.org has also created an annual event to help with mitigation efforts: lionfish derbies. These derbies, held in numerous locations, are single day competitions to collect and remove as many lionfish as possible. Teams collect lionfish by netting or spearing while SCUBA diving, free diving, or snorkeling. Lionfish derbies typically begin at sunrise and contestants must have their catches in to the scoring table by 5:00pm. Prizes are awarded to the contestants who bring in the most fish, the biggest, and the smallest individual fish. REEF.org has done a great job at using these contests to educate as well. The night before each event, all contestants must attend a “Captain’s Meeting,” where they learn about lionfish biology, ecology, impacts, harvesting methods, and derby rules. During the event, spectators are welcomed to observe scoring, and can also observe lionfish dissections and filleting demonstrations. Spectators can obtain free samples of prepared lionfish and are encouraged to ask questions they may have about the invasive fish. REEF.org began hosting lionfish derbies in 2009, and since then have brought in almost 15,000 fish.

Lionfish-Scuba-Diving-ExperienceIt is clear that mitigation efforts can make a significant impact at the local level; however, it is still unknown how significant those impacts are at the macro level. Raising awareness is one of the major goals of the aforementioned mitigation techniques and is important for the eventual control of this invasive fish. Healthy coral reefs and lionfish are struggling to coexist in the Western Atlantic, and we need our reefs to be healthy, as many people depend on these fragile ecosystems for their livelihoods. So order lionfish at your next dinner out, and whenever you see one while diving or snorkeling, spear it, but please be careful!

Article by Hillary Ballantine:

Hillary Ballantine is from a small town in central Ohio, a long way from the ocean. She became mesmerized by marine life at a very young age, and always knew she wanted to help save the whales. She graduated from Coastal Carolina University with a B.S. in Marine Science and a B.S. in Biology, and is currently attending graduate school at Antioch University New England, earning a M.S. in Environmental Studies with a concentration in Conservation Biology. She has worked with educating the public on marine life at Myrtle Beach State Park, and hopes to further her experience in both the education and scientific aspects of conservation.