Whale shark carcass washes ashore on Sanibel Island beach; FWC biologists to get samples

Show Caption Hide Caption Video: Dead whale shark washes up on Sanibel Beach A dead whale shark washed up on a Sanibel beach.

The carcass of a 21-foot-long adult whale shark washed up off West Gulf Drive on Sanibel Island on Sunday morning.

Biologists from the Florida Fish & Wildlife Commission were on their way to where the carcass was rolling in the surf to collect samples.

"I'm sure they were going to try to determine a cause of death," said Brian Norris, an FWC spokesman.

Marine biologists from the Bailey-Matthews Shell Museum were on the beach near the Island Inn on Gulf Shore Road where the shark came ashore.



The shark’s cause of death was not immediately known, but Shell Museum marine biologist Rebecca Mensch said the shark showed little signs of decay and likely died Saturday night or Sunday morning.

The shore where the shark was found is littered with dead fish as well, causing many to speculate that red tide may have been the cause of the animal's death.

"The research is still ongoing whether or not these animals are susceptible to red tide or, if they are, how sensitive are they," Mensch said. "So, that's not something one way or the other that you can say it was red tide."

A tissue sample and toxicology test that can take anywhere from days to weeks to provide results may give the biologists answers as to whether red tide affected the shark, she said.



The museum has been working with Mote Marine Labratory and Aquarium in Sarasota to determine if the shark was one of the animals that Mote tracks. But when a team of three marine biologists looked over the shark for tagging, it did not appear to be one of Mote’s sharks.

The shark drew a crowd of dozens of beachgoers, many of whom were snapping pictures and taking video, in awe of the giant animal.

“You’ve been to like aquariums and stuff and you’re like ‘This is the wildlife’ but seeing it up close and in nature it’s shocking,” said Lily Miller, a 16-year-old from Cleveland, Ohio who was visiting Sanibel for the first time with her family. “Especially seeing a huge dead shark. It breaks my heart and it’s not something you ever expect to see, especially when you’re out in the (gulf).”

While whale sharks aren't something you might expect to see on Southwest Florida beaches, they are actually quite common on the other side of the coast, near Cozumel, Mexico, where they are currently mating, Mensch said.

“This part of the Gulf of Mexico stays shallow really, really far — about 100 miles — so this really, really shallow water is not a normal place you expect a huge animal like this to be in," she said.

Mensch added that it's hard to tell where the shark was when it was last healthy because strong currents and wind could have carried it to Sanibel's shore.



The plan is to let the shark decay naturally in the Gulf, Mensch said, warning beachgoers to steer clear of the animal.

More: Sharks and gators sometimes go tooth-to-tooth along the Florida coast

More: Five sharks found in Southwest Florida waters

More: YETI the great white shark surfaces off Southwest Florida's coast, Hilton close

The tides and waves can easily create an environment where one can slip and fall under the shark, which likely weighs thousands of pounds, she said.

Scavengers that will be attracted to the shark's carcass as it decays are another danger, Mensch said. With varying scents and murky water on a wavy day a scavenger wouldn't be able to tell the difference between a person's foot and the shark's flipper.

According to the University of Florida, whale sharks are the largest fish in the sea, growing longer than 40 feet. They exhibit unique pattern of blue-gray to brown coloration with white spots centered between pale horizontal and vertical stripes.

They are filter feeders, often swimming near the surface of the open sea, gulping in water and filtering everything from plankton and fish eggs, to crustaceans and schooling fish, to occasional larger prey like squid or tuna.

Despite their size, they are considered harmless to humans, and will often interact with divers to the extent of allowing the divers to grab on to a fin and hitch a ride.

Gina Young, who comes to Sanibel every year from Alabama said the shark was "gigantic" and it was "sad but amazing to see the shark in person.

"Every time we come to Sanibel, it's something different," she said. "This year, it's the whale shark."