In a new study of South Florida’s sharks, it has been revealed that the fearsome bull shark is actually one of the most common species.
The fear-inducing and deadly Bull Shark turns out to be fairly abundant in South Florida according to recent research on their numbers there but it isn’t the one most commonly found.
“This is a formidable predator that could pose a risk to humans,” said Neil Hammerschlag, research associate professor, Shark Research and Conservation Program at the University of Miami Rosenstiel School of Marine & Atmospheric Science, and co-author of the study. “But with the number of people that use the ocean off Miami for recreation, it just shows these animals are not out to hurt humans. Humans are obviously not on the menu.”
The study, which will appear in the scientific journal Ocean & Coastal Management, examined 3,398 sharks caught and released off Miami and the Florida Keys from 2009 to 2021. They ranged in size from a 20-inch Atlantic sharpnose shark to a 14-foot 7 inch great hammerhead. Of those identified 15 species of shark ranging from the most common nurse followed by blacktip, lemon and bull. The study counted 1,335 nurse sharks, 650 blacktips, 314 lemon sharks and 253 bull sharks.
The study sought to establish a baseline for the status of South Florida’s sharks—how many were there, what species they belonged to, where did they hang out at different times of the year. With this study in hand, scientists will be able to monitor the region’s shark populations for changes that could call for altering rules on fishing and water pollution.
“This study is the first and only population assessment of large coastal sharks published to date in Miami and the Upper Keys,” said Abigail Tinari, a master of science student at Rosenstiel and lead author of the study.
“It lets us know what’s here, and that can be compared in the future to know how these species are doing,” she said. “It gives you an idea of what areas the sharks are using and the current number and abundance of the sharks, so they can be compared for future studies and future management.”
Resilient and strong, the bull shark takes on a wide frame that is heavier than many of its counterparts. They are responsible for 18% of attacks in Florida since 1882 according to International Shark Attack File data which comes out at University of Florida.
“The white, tiger and bull sharks are the ‘Big Three’ in the shark attack world because they are large species that are capable of inflicting serious injuries to a victim, are commonly found in areas where humans enter the water, and have teeth designed to shear rather than hold,” the International Shark Attack File’s web page states.
The world’s three most fearsome species of shark, the tiger sharks, great white and bull sharks all showed up in lower numbers off Florida as they do every year. The survey found 100 tigers ranging from 3 1/2 feet to 13 feet long with only a single great white identified at 11 ft long.
The other two species known for their ferocity – the tiger and bull shark- also made an appearance but not nearly like what is expected when these apex predators are reported on television or online news sources.
A surprising finding in the study was that great hammerhead sharks, who are typically found near-shore and have a high mortality rate due to their large size and fragility, were among the fifth most common species.
“They’re globally endangered,” Hammerschlag said. “They’ve undergone very large declines. But off Miami, it’s one of the more common species.”
The remaining sharks sampled included 210 sandbar sharks, 178 blacknose sharks, 67 Atlantic sharpnose sharks, 22 scalloped hammerhead sharks, 13 Caribbean reef sharks, 11 bonnethead sharks, five dusky sharks and one spinner shark.