By Julio Ochoa
Wednesday, March 14, 2007
Dead sharks are crashing the area's spring break party.
Dozens of juvenile bonnethead sharks and stingrays washed ashore Tuesday on Fort Myers Beach and Lovers Key State Park. As many as 25 sharks between 1 and 2 feet in length were reported on the shore of Lovers Key alone.
The deaths could be related to a red tide bloom off the coast, a scientist said.
The Florida Fish and Wildlife Research Institute reported low to medium levels of red tide in some areas off Sanibel, Fort Myers Beach and Lovers Key on Friday.
"It looks like the red tide has been hanging out on the bottom off the coast," said Rick Bartleson, a scientist for the Sanibel-Captiva Conservation Foundation. "I don't know if that is what's killing those sharks, but I've been expecting to see some dead fish."
Over the past few months, dead and dying scallops have washed ashore in large numbers on Sanibel Island.
When the Fish and Wildlife Research Institute studied the water in the area around Sanibel, it found evidence of red tide, said Wendy Quigley, spokeswoman for the institute.
"We can't pinpoint that as the cause; however, red tide appears to be present in that area," she said.
Bonnethead sharks feed primarily on crustaceans, such as blue crab and shrimp, and on mollusks. The small shark feeds by swimming across the ocean floor and moving its rounded, shovel-like head across the bottom, looking for disturbances.
The Florida Fish and Wildlife Research Institute will get samples from the sharks to determine the cause of death, Quigley said.
"We are aware that red tide is present in the area, and at this point we're thinking it may be related to red tide," Quigley said.
A medium concentration of red tide could contain anywhere between 100,000 and 1 million cells per liter of Karenia brevis, the organism that causes red tide.
"That's kind of misleading, because if you have 10,000 cells, it can cause a fishkill," Bartleson said.
Red tide can be found throughout the water column, Quigley said.
The dead sharks picked a bad time to show up in Lee County.
With spring break in full swing, the area is at the height of its busy season.
A recent outbreak of red drift algae sent officials to the shores of Fort Myers Beach and Sanibel to rake up the mess.
"Events like red tide or red drift algae do create a bit of a challenge for us," said Tamara Pigott, deputy director of the Lee County Visitor and Convention Bureau.
The bureau sets aside a portion of bed tax revenues for an emergency beach cleanup fund. Some of those funds will be used to reimburse Fort Myers Beach and Sanibel for algae raking. If red tide were to cause a major fish kill, the emergency beach cleanup fund could be tapped to clear the smelly mess.
"We're very steadfast in trying to make sure our visitors have a great experience," Pigott said. "That's why those funds are there."
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Published in Naples, Florida, USA by the E.W. Scripps Co.