Stone crabs take hit from red tide

SARASOTA, Fla. (FOX 13) - Stone crabs have been a holiday delicacy in Florida for generations, but parts of the state may have fewer stone crabs for years because of red tide. That's according to preliminary findings at Mote Marine Laboratory in Sarasota.

Scientists have collected samples of red tide from several areas and exposed stone crabs to the toxin while observing them. 

"Typically, the first to go is the antenna, and next the mouth," said laboratory technician Cody Cole, describing how exposure effects the animals. 

Scientists say the crabs have a natural resistance and can bounce back, except when the bloom is abnormally long. 

"Once it gets beyond the three-day mark, we begin to see an increase in the animals' stress response and we also see an increase in the mortality of the animal," said Philip Gravinese, the lead researcher. 

He says the crab larvae is even more susceptible. "That's another reason a couple of years beyond the bloom we see a decrease in catch.”

The study is ongoing, but scientists believe crabs are killed by a one-two punch: First, the red tide toxin, then depleted oxygen in the water. 

"And we have video evidence showing these stone crabs belly up because they weren't able to get the oxygen needed," continued Gravinese. 

LINK: Full FOX 13 red tide coverage

Cole said stone crab catches north of the Tampa Bay area and in the Florida Keys have been steady this season, but off Cortez and Sarasota, the fishery has been significantly impacted.