Warming oceans may shrink Florida stone crab supply

By Zachary Fagenson

MIAMI (Reuters) - Researchers working with the National Oceanic and Atmospheric Administration say warmer, more acidic oceans may reduce the number of stone crab hatchlings as the availability of the popular, pricey delicacy dwindles.

A study using water temperatures and carbon dioxide concentrations predicted for the end of this century by climate change scientists found the number of stone crab larvae fell by nearly 40 percent under those conditions.

"There’s already something out there that’s been making the catch smaller and so it becomes concerning when you add these other stressors,” said Philip Gravinese, a marine biology doctoral student at the Florida Institute of Technology in Melbourne.

Initial estimates from the Florida Fish and Wildlife Conservation Commission show 896,199 pounds of stone crab claws were hauled in 2013. That’s a fraction of the 2.7 million pounds of claws hauled in 2012, worth $25.1 million, and the 3.4 million pounds collected in 2000, a bellwether year.

Most recently fishermen have attributed the paltry catch to a variety of factors, including a boom in octopus, which feed on the crabs, and last year a red tide that killed off much of the crabs’ food source.

The shortage increased demand and pricing but also forced some fishing companies to lay off staff and operate on thin margins.

Gravinese is also studying the impact of changing oceans on the crabs’ ability to develop the rock-hard shells that diners smash with wooden mallets to reveal the meat.

While thinner shells might make the crabs more susceptible to predators, Gravinese said there has been evidence of stone crabs reproducing in places where the seas are, for short periods of time, already as warm as the end of the century predictions.

“Some of those females may be OK ... and may be in the process of developing mechanisms to cope with the changes,” he said.

(Editing by David Adams and Jim Loney)