A great white shark named Miss Costa surfaced long enough off Key West on Sunday for the group Ocearch to get a ping from her location south of the tropical isle.
Miss Costa, who was tagged by Ocearch in 2016 near Nantucket, was 12-feet, 5-inches long and weighed 1,668 pounds at the time. She was named for Costa sunglasses, a brand that sponsors Ocearch work.
It’s no surprise that Miss Costa has headed south for the winter.
Many white sharks make the migration out of the cold waters in the northeast to Florida’s warmer climes this time of year.
Florida is a wintertime stomping grounds for the great white, and as their numbers grow from two decades of conservation efforts, more encounters are likely, researchers said.
“I call them my snowbirds,” said Gregory Skomal, a scientist with the Massachusetts Division of Marine Fisheries in a January interview. “Many of the sharks leave the Cape and go down to Florida in the winter.”
People may be more familiar with Miss Costa’s comrade Katharine, who gained notoriety in 2014 and years since for her Florida sojourns.
A study in 2014 led by National Marine Fisheries shark expert Tobey Curtis compiled a database of 649 confirmed white shark sightings back to the 1800 and found a clear pattern of white sharks wintering off both Florida coasts and through the Carolinas. Summers are spent in New England waters.
The study also found that white sharks were most often sighted in waters over the continental shelf. More than 90 percent of the sightings were in waters 330 feet deep or less, with the median depth of about 100 feet.
Because the continental shelf doesn’t extend far off Palm Beach County’s coast, white sharks may be funneled between the coast and the shelf’s edge, said Dean Grubbs, associate director of research at the Florida State Coastal and Marine Lab in an interview earlier this year.
“If you are in Jacksonville, it’s 50 miles to the edge of the continental shelf, but down in Jupiter, it’s only a few miles,” Grubbs said. “If animals want to stay in that shallow zone, they are going to come closer to shore.”
Warmer waters in the Gulf Stream could increase the funnel effect, acting as a thermal barrier.
Curtis found that sharks were most often seen in water temperatures between 57 and 73 degrees. The warmer Gulf Stream varies in distance from Palm Beach County’s coast but can have its western edge move in as close as 1 mile.
“But realize, a lot of this is conjecture,” said Skomal, who worked with Curtis on the study. “If most fishing occurs on the shelf, that’s where the sightings are going to be. That’s why tagging is so important.”
Casual beach bathers and surfers shouldn’t be overly concerned, Skomal said.
No one has been bitten by a white shark in Florida, according to the International Shark Attack File, and there’s nothing to bring them near shore.
They are more likely to come close to the beaches of Cape Cod, where seals pile up along the coast, said Skomal, who spent time last year in the waters off Palm Beach County trying to solve a white shark secret — what are they feasting on here.