Invasive red lionfish (Pterois volitans) from the Pacific Ocean are eating their way through the coral reef fish populations off the Atlantic Coast and in the Caribbean Sea. And none of the local predators—not even barracuda or sharks—seem able to stop them, perhaps because the invaders' 18 needlelike dorsal fins (the spines in the photo above) are venomous. That's the conclusion of researchers who surveyed 71 reefs in different areas of the Caribbean over 3 years. The only reefs with lower lionfish populations are those that are protected , and where reef managers have targeted the invaders for removal, the scientists report this month in PLOS ONE. Equally alarming, lionfish populations have also been discovered at depths of more than 90 meters, according to another group of researchers. That team used a five-person submersible to explore a cargo ship intentionally sunk off the coast of Fort Lauderdale, Florida, in 1986 to create an artificial reef. Here, the lionfish are big: about 41 centimeters in length versus the more typical 31 cm for lionfish in shallower waters. The scientists, who made the announcement in a university press release , worry that the larger females will produce far more offspring than smaller fish. Further, there is no easy way to selectively trap lionfish at these depths. The biggest hope for the invaders' removal? Humans, who accidentally introduced them in the first place. You're encouraged to catch and eat as many as you can; they're delicious, once the venomous spines are removed, the researchers say.