11-foot shark found dead off South Florida. Clue was in its mouth, experts say

Apex predators seldom just drop dead, so an explanation was needed when the carcass of a seemingly healthy 11-foot, 4-inch great hammerhead shark was discovered off southeast Florida.

Great hammerheads have few natural enemies — other than killer whales — and it was clear the shark had not been attacked.

So what killed it? Closer inspection revealed a clue in the shark’s mouth.

It was a large hook, indicating the majestic female had died as a result of catch-and-release sport fishing, according to a social media post shared Aug. 18 by the Marine Megafauna Foundation: Americas.

The discovery originally surfaced Aug. 17 on the Elusive Endeavors Instagram account of Capt. Bryant Turffs, a biologist and co-creator of the Florida Manta Project.

“This shark almost certainly perished post release ... which can occur due to the stress of being captured,” Elusive Endeavors wrote on Instagram.

“This is more likely in instances where there is a long fight, where the shark is kept out of water for photos or gear removal, and is more likely with sensitive species like great hammerheads.”

The shark was discovered Aug. 14 by a team monitoring sea turtle nests about a mile north of the public beach in Delray Beach, Turffs told McClatchy News in an email.

He estimates it had been dead 12 to 24 hours. The beach is a popular spot for “nighttime shore-based shark fishing,” which includes hauling the sharks out of the water for photos, Turffs said.

“When I arrived on scene I was saddened to see this beautiful, otherwise healthy shark upside down and dead in the surf. Having experienced similar events in the past, I knew to check for a hook and wasn’t surprised to find one,” Turffs said.

“I know opinions about sharks vary widely and that they always deserve healthy respect. I have enjoyed swimming with many sharks including hammerheads under natural circumstances, and was a bit more depressed by this episode to think that it could have been an individual I had recently seen alive in the greater area.”

Turffs reports he was in the area that day doing research on endangered giant manta rays with the Marine Megafauna Foundation.

News of the carcass discovery prompted concerns on social media that a threatened species is being further endangered for sport.

“This is so unbelievably heartbreaking. A lot of people think that catch-and-release fishing of great hammerheads is not dangerous to the animal,” We Love the Sea Foundation director Angela Warrior wrote on the Marine Megafauna Foundation’s Facebook page.

“These sharks are very fragile, they get extremely stressed and will release lactic acid which eventually shuts down their organs and they die.”

Delray Beach is about a 55-mile drive north from Miami.

This story was originally published August 22, 2025 at 9:29 AM with the headline "11-foot shark found dead off South Florida. Clue was in its mouth, experts say."