Aquatic Invasives

Invasive Lionfish

What’s for dinner?  Hopefully it’s lionfish!

Bermuda has just hosted the “Eat Lionfish Chefs Throwdown,” a lionfish cooking competition organized by 11th Hour Racing whereby featured celebrity chefs from the host nations of each America’s Cup team, competed to create the best lionfish dish.  Chef Chris Kenny, Necker Island’s Head Chef, won the prize, and all involved were winners in raising awareness.

Lionfish, specifically, Pterois miles and Pteroisvolitan, are native to the Indian Ocean, Southern and Western Pacific Oceans and the Red Sea, where they have sharks, cornetfish, grouper, large eels, frogfish and other scorpionfish as natural predators. However, in the Western Atlantic Ocean, Caribbean Sea and in the Gulf of Mexico where they do not have natural predators,invasive lionfish are an immense and growing problem. The first marine reef fish invasion of its kind, some say this is the worst man-made ecological disaster ever witnessed.¹

The efficiency of invasive lionfish is impressive!  They are literally out-breeding, out-eating and out-living native fish and other marine species. 

BREEDING:  A female lionfish becomes sexually mature at one year old and can release up to two million eggs per year.  Many of those eggs become larvae and then juvenile lionfish in environments where they can live relatively free from environmental pressures.

EATING: Lionfish eat an amazing assortment of species including fish (the young of important commercial fish species such as snapper and grouper),invertebrates, mollusks, shrimp, crabs, juvenile octopus, squid, juvenile lobster and sea horses and in great quantities. Lionfish have been seen consuming 20 small fish in a 30-minute period and eating prey up to 2/3rds their size. Their stomachs can expand up to 30 times their normal size after a meal. These voracious appetites threaten both individual species as well as entire reef ecosystems. Some studies have shown that a single lionfish can reduce native marine creatures by 79% in its range within just 5 weeks. ² Many of the species lionfish eat, such as grazers and cleaners, are ecologically critical to the health of the reef because they eat the algae that cover reefs, keeping the algae levels low enough that coral can survive and reproduce. Grazers include parrotfish, goatfish, wrasses, surgeonfish and tangs. Reefs are home to 25% of all known marine species and serve as shelter and protection to schools of many juvenile marine creatures.

Because they are so flexible, lionfish are seldom without food but, if conditions require, lionfish can live without food for 3 months and beyond and lose very little body mass as a result.

LIVING: Lionfish have impressive lifespans of 15-20 years and are spectacularly versatile in their ability to adapt to and thrive in different environments. For example, they have been spotted in water as shallow as 1’ deep and in water beyond 1,000’ deep. They live in oceans as well as brackish water estuaries and are able to tolerate water temperatures down to 50 degrees Fahrenheit. Sailors for the Sea http://sailorsforthesea.org, a nonprofit organization in Newport Rhode Island that unites boaters to protect the ocean, has witnessed lionfish in the cold water North Atlantic but claims “they don’t live long in our cooler waters and are unable to survive the tougher winters.”³ On top of all of this, lionfish appear biologically resistant to most diseases and parasites that affect native fish ⁴.

WHAT CAN BE DONE?

Obviously, many people are working on solutions to this devastating problem. A number of techniques have been tried, among them, hunting lionfish (spearguns, pole spears and Hawaiian slings have proven most effective), training native species to eat lionfish and zapping and collecting lionfish with robots. 

Surprisingly, direct action by lionfish hunters is the most viable method for controlling lionfish currently in the very small areas divers can access. REEF.org⁵ is one of several organizations that sponsor lionfish derbies, in which hunters compete for the largest/smallest and most lionfish kills. It’s a nice way to raise awareness; the public is generally invited to participate, watching scoring, filleting and cooking demonstrations and tasting lionfish samples. And, the areas regularly maintained by such hunters have seen a demonstrable rebound of native fish over time.

Some groups have tried training sharks and groupers to eat invasive lionfish with limited success and unintended consequences. In one experiment, the grouper were clearly afraid of the lionfish and appeared to prefer starvation to eating lionfish. Also, because fish don’t train their offspring, each generation of fish would have to be trained to eat lionfish, making this method cost prohibitive. Lastly, once trained, sharks, in particular, thereafter equate lionfish with food, putting lionfish hunters in significant danger.

Robots In Service of the Environment (RISE) is a nonprofit organization attempting to solve the lionfish problem with robots that stun and then capture lionfish. One key benefit to using robots is that they can dive significantly deeper than humans and can potentially cover extensive areas. If successful, co-founder Colin Angle says, robots could capture enough lionfish to establish a new market in which “chefs can turn an environmental hazard into gourmet cuisine.” Angle wants lionfish hunting to become an online sport whereby users pay to hunt and capture fish by operating robots from an application. If it takes off, that would be an amazing way to both capture lionfish and raise awareness!

The only way to possibly solve this problem is ifscientists, technologists, fishermen, divers, chefsand consumers coordinate their efforts. So, back to dinner, I’m taking the pledge to improve my healthy choices⁶ and order/buy delicious lionfish whenever possible.

1. https://lionfish.co
2. MarkHixon et al (2009)
3. http://sailorsforthesea.org/programs/ocean-watch/lionfish-invasion (Kimball et al. 2004)
4. https://lionfish.co
5. REEF also holds lionfish jewelry workshops which encourages yet another consumer market that promotes lionfish removal.
6. Nutritionally lionfish have the highest concentration of omega-3 in their category, scoring above farmed tilapia, Bluefin tuna, red snapper and grouper.  (Scientists from Roger Williams University, REEF, NOAA and the North Carolina Sea Grant (Morris et al, 2011) study detailing the nutritional benefits of lionfish consumption)

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