Countless calico scallops washed ashore Friday, scattering a mystery over a mile-long stretch of Satellite Beach.
Local beachgoers say they've never seen anything like it, while state biologists — as they investigate the matter — speculate wind and waves brought them in.
Others aren't so sure.
"Our Fish and Wildlife Health staff have samples and are currently investigating further," Carly Jones, a spokeswoman with the state's Fish and Wildlife Research Institute, said Friday. "It is most likely that a combination of wind and/or wave swells washed them ashore."
Kevin Johnson, a professor of Ocean Engineering and Marine Sciences at the Florida Institute of Technology, doubts that's the case.
"Their typical habitat is 30-40 meters deep," Johnson said Friday. "I don’t think we’ve had winds that could do that without some help. I believe something weakened or killed them ahead of washing ashore."
Johnson said the scallops are "either alive and dying or freshly dead."
The soft tissue between their shells was visible, he noted. "That is their internal viscera, including foot, gills, adductor muscle, etc."
"So this does pose a bit of a mystery – a sudden mass death event," Johnson added. "If we’d had an unusual storm (winds/rough waves), then I would speculate they were just dislodged from their sandy subtidal habitat. But we haven’t really had that type of a storm, and their habitat is usually 30 meters deep or more."
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While they have been commercially harvested in the past, calico scallops collapsed as a going commercial concern four decades ago.
"Like so many fish and shellfish which have been overharvested, it is hard to find very big ones any more," Johnson said.
If the dead and dying scallops were along 10 or 20 meters of the beach, Johnson said he'd think it might be that someone caught them and poured them out nearby.
But the larger expanse along the beach suggests some sort of “natural” phenomenon."
Calico scallops are found throughout Florida's coast.
"If their plight is natural, something has weakened their ability to stay put on their home on the sandy seafloor," Johnson added.
Possibilities of why they washed up include disease (viral, bacterial, fungal); temperature extremes; rapid changes in salt content in the ocean; and parasites, he added.
According to the Florida Fish and Wildlife Conservation Commission's website, "Infection by a parasite of the genus Marteilia may have been responsible for a calico scallop population crash recorded off Cape Canaveral along Florida’s east coast in 1991. The parasite appears to infest the calico scallop’s digestive gland to such an extent that they starve to death."
This article originally appeared on Florida Today: Scallops wash up on Florida's Satellite Beach puzzling FWC, biologists