Nightly News | July 05, 2013
>>> going on with an underwater predator that causes destruction wherever it goes. kerry sanders on the hunt in florida.
>> i would expect we'd see quite a few down there.
>> reporter: looking beneath the clear blue waters of florida keys is a beautiful, but frightening fish. poisonous, abundant and with an appetite that won't quit.
>> u.it's a big fish vacuum cleaner.
>> reporter: in eight years, lion fish have proliferated off the east coast .
>> it only took a handful of these fish to get together to start reproducing, once that happened, oceans are all connected and it spread like wildfire, really.
>> reporter: where a few once were found off the bahamas, they are now up to rhode island , south to the caribbean and they started showing up in a wide area of the gulf of mexico . scientists worry they will devastate native fish populations.
>> we have some evidence that groupers occasionally will eat them, but once a grouper who has experienced that spine, they may never eat another one, because those spines are very venomous.
>> reporter: as for natural predators, a team dives off the florida keys almost every day. they capture and kill what they can, but it's a monumental task. a lion fish lays up to 30,000 eggs every four days. more than 300,000 fish now inhabit reefs in the keys. three times the population from two years ago.
>> a bag of lion fish .
>> reporter: scientists concluded they will never get rid of the fish in the area. best way to win? eat them to beat them. cooked at more than 400 degrees, these white flaky fish are no longer toxic. biologists believe if they can create a market, maybe commercial fisherman can hold this menacing invasion in check. kerry sanders , nbc news, the florida keys .