LONG KEY (CBS4) – South Florida divers will be chasing lionfish again in the waters off the Florida Keys this weekend hoping to win cash and prizes.

The second annual round of lionfish derbies begin Saturday at a resort in Long Key in the Middle Keys. The derbies are hosted by the Florida Keys National Marine Sanctuary and the Reef Environmental Education Foundation.

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The derbies continue in August in Key Largo and in November in Key West. All divers are given puncture-resistant gloves to protect them from the lionfish’s venomous spines.

Last year, more than 40 teams of divers caught more than 650 lionfish in the waters off the Keys.

The lionfish is an invasive species that lacks natural predators in the Atlantic. They are originally from the Indo-Pacific Ocean.

No one knows how the lionfish got here. There are a number of theories ranging to an aquarium that exploded during a hurricane to a luxurious aquatic themed hotel that incidentally leaked lionfish eggs into the Caribbean. Scientists have documented sightings going back decades but never like this. A United States Geological Survey map dating back to 2000 shows the lionfish beginning to appear along the Eastern seaboard. Starting in 2009 something dramatic happened. The entire Caribbean and Florida Keys became saturated. It appeared to happen almost overnight and scientists can’t explain it.

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Scientists worry they will disrupt the balance of the marine ecosystem here. The growing number of lionfish has impacted the populations of indigenous fish, because they eat important juvenile reef species such as grouper and snapper.

There are believed to be thousands of lionfish swimming along South Florida’s shoreline and it’s considered a fish invasion.

That’s why officials hold the lionfish derbies. It’s an effort to thin the numbers of the ocean-dwelling predators.

The mane-like assemblage of spines that give the fish its lion-like appearance are tipped in poison that can cause severe pain, swelling, nausea, headaches and convulsions. However, the fish can be safely handled once the spines have been removed and many people fillet lionfish and cook them up just like any other fish.

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