Divers Help Quell the Roar of Invasive Lionfish

A lionfish near the Caribbean island of Bonaire (Photo by Anne Pharamond)
A lionfish near the Caribbean island of Bonaire (Photo by Anne Pharamond)

It seems strange to mark the location of a fish, doesn’t it? They can swim and move away from the marker, right? I wonder while standing on a dock waiting for the boat that will take about ten of us out to a reef. There, we will scuba dive for fun and also mark the locations of lionfish, an invasive species in the Caribbean.

Volunteer divers on the Dutch island of Bonaire are helping Bonaire National Marine Park eliminate invasive lionfish from its coral reefs by marking the locations where the fish are found. A diver who spots a lionfish is instructed to attach a small flag, provided by the park, to a rock near the fish.

The answers to my questions about marking fish locations become clear once I splash into the water and see the fish and flag markers for myself.  Swimming along sections of reef, I saw dozens of flags that had been placed there by divers and each had one or more lionfish hovering nearby. It turns out that lionfish don’t stray far from their particular nook of reef. They stay near the markers.

It’s illegal to hunt or in any way harm marine life in the waters surrounding Bonaire. Except, that is, for lionfish.

They are beautiful fish, placidly fluttering their glitzy ruffle of fins, and hovering next to their flags.  Yet, a voracious appetite for reef fish combined with a high rate of reproduction and no known predators in the Caribbean make lionfish a threat to biodiversity. Native to the Pacific, the lionfish is an invasive species in the Caribbean.

On October 26, 2009 the first lionfish was spotted in the shallow waters off the coast of Bonaire. Now, a year and a half later, they are common.

In November 2010, for the first time in 40 years, the use of spear guns was allowed on Bonaire’s reefs, specifically to kill lionfish. One hundred ELF spears were brought to the island, the weapon of choice when in comes to lionfish elimination.

A group of spear-toting volunteers, known informally as “eliminators,” look to an online list of lionfish sightings reported and marked by scuba divers with flags to know where to hunt the fish. The “eliminators” remove the markers from the reef when they remove the lionfish one by one.

More people who wish to wield a spear are getting involved. Dive instructor and lionfish eliminator Annie Olszewski at Bonaire Dive and Adventure trains divers to help with lionfish elimination. She recently developed a day-long PADI Lionfish Awareness and Elimination course and has trained two dozen people to play a more active role in reducing the lionfish population.

Bonaire’s lionfish eliminators are getting to know each other while using social media to hunt this invasive species. Their Facebook group, “Bonaire Lionfish Hunters,” includes posts about the one that got away, the areas of the reef they covered, and interesting new studies about lionfish biology and ecology. Annie tells me that she recently saw a lionfish when she was diving without her spear. She posted the location on Facebook and, shortly, another eliminator who saw her post caught the fish.

Throughout the Caribbean and Atlantic lionfish have been multiplying rapidly since the fish was spotted off the coast of Florida in the early 1990s. The first lionfish to make its way to the Caribbean may have been released from an aquarium tank either accidently or intentionally.

As the lionfish have spread throughout the Caribbean, so have innovative projects that get people involved in the effort to stop the fish from causing harm to reefs. Lionfish Derby events in Florida and the Bahamas award prizes to the volunteers that catch the most fish. Researchers from the USGS are learning more about lionfish genetics from the fish caught during the Florida Lionfish Derby.

Restaurants are starting to feature food made from lionfish too. There’s even a Lionfish Cookbook of recipes for adventurous chefs, making humans perhaps the only lionfish predator in the Caribbean.  From what I hear, this invasive species is tasty.

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This post was originally published on Citizen Science Buzz, a blog on TalkingScience that highlights science projects that are helping us better understand our planet and the Universe.

Categories: Animals, Biology, Citizen Science, Ecology & Environment, Ocean & Water

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