Scientists investigate after deepwater sunfish wash up on Ponte Vedra, St. Augustine and Vilano beaches

Jacksonville.com: Scientists investigate after deepwater sunfish wash up on Ponte Vedra, St. Augustine and Vilano beaches

Florida fish and wildlife officials are investigating the recent deaths of three massive ocean sunfish found less than a week apart on three St. Johns County beaches, including Ponte Vedra Beach.

On Feb. 16, a 9-foot, nearly 500-pound sharp-tailed mola was found washed up on St. Augustine Beach near A Street around 8 a.m.

Three days later, on Feb. 19, another one washed up on Ponte Vedra Beach, near 159 Sea Hammock Way, behind the Old Ponte Vedra condominiums. Officials had little information Wednesday about the creature's size.

Then a deputy found the carcass of a 7-foot, 300-pound sunfish about a quarter-mile north of the Surfside ramp on Vilano Beach around 2 a.m. Monday.

Five other sunfish have been found along East Coast beaches since Jan. 11, said Carli Segelson, Florida Fish and Wildlife Conservation Commission Research Institute spokeswoman.

"These species are not frequently seen because they are deepwater fish," she said.

Last year, seven washed up about the same time of year. Scientists still haven't determined their cause of death and they don't anticipate determining the causes for the most recent ones for months, said Micah Bakenhaster, FWC research division biologist.

"It could be something wrong when they are close to shore, but it's hard to say," he said. "Most of the ones we've seen have not shown any obvious signs of disease."

Biologists plan to collect the species' tissues, organs, gills, hearts and brains to look for parasites and test for toxins. They will also consider the creatures' histology, which tells if something is happening in the ocean, or if they have diseases or something wrong internally.

The fish could also be dying of natural causes, researchers said.

Little is known about the ocean sunfish, also known as the mola mola, or common mola, which is the heaviest known bony fish in the world. With average adults weighing about 2,200 pounds, the flat body fish resembles a fish head with a tail.

They are brown to silvery gray or white, with a variety of mottled skin patterns. Sunfish can be as wide as they are long when their dorsal and ventral fins are extended.

"They are hard to study," said Bakenhaster. "Most of the information that we have about them come from specimens that wash ashore."

The number of ocean sunfish in the world is also unknown. Adult sunfish are vulnerable to few natural predators, but sea lions, orca whales and sharks will consume them.

To report fish kills, call the fish kill hotline at (800) 636-0511.