- Title: Sharks frequent waters near crowded urban beaches, new study finds
- Date: 30th August 2022
- Summary: MIAMI, FLORIDA, UNITED STATES (FILE) (REUTERS) VARIOUS DRONE SHOTS OF MIAMI BEACH (MUTE) PEOPLE JUMPING OVER WAVES WIDE SHOT OF PEOPLE IN OCEAN PEOPLE WALKING ALONG CROWDED BEACH
- Embargoed: 13th September 2022 10:42
- Keywords: University of Miami city beaches sharks urban beaches urbanization
- Location: MIAMI, FLORIDA, UNITED STATES / AT SEA / UNIDENTIFIED
- City: MIAMI, FLORIDA, UNITED STATES / AT SEA / UNIDENTIFIED
- Country: USA
- Topics: Life Sciences,Science,United States
- Reuters ID: LVA002914917082022RP1
- Aspect Ratio: 16:9
- Story Text: Beachgoers in urban areas are probably swimming near sharks without even realizing it, according to a new study by experts at the University of Miami, who tracked the ocean predators' movements off the southern Florida city's coast.
The director of the university's Shark Research & Conservation Program, Neil Hammerschlag, said he wanted to see whether, in a rapidly urbanizing world, sharks steered clear of densely populated areas.
"We really thought they would, because studies of big land predators have found that wolves, and bears, and kind of the big land carnivores tend to avoid being around big cities," he said. "[But] that's not at all what we found with the sharks."
Instead, researchers discovered that sharks were spending a lot of time in waters where people like to take a dip. But, Hammerschlag said, that should not be cause for alarm.
"Although this might make you a bit nervous, to me it just proves the point that sharks really don't want to bite people, and that, in fact, sharks really tolerate people and tend to avoid them," he said.
The sharks' movements were monitored for several years using a technique called passive acoustic telemetry, Hammerschlag said.
Three different species of shark - Bull, Nurse, and Great Hammerhead - were tagged with small transmitters that emit ultrasonic sounds. The researchers then placed receivers - or "listening stations" - under water off the coast of Miami and the Florida Keys to collect data.
"When a shark swims within a few hundred feet of one of those listening stations, it can detect that transmitter, hears it, and will record that...that shark swam by that location," Hammerschlag explained.
He said it was still unclear why the sharks were not, in fact, repelled by cities, given their high levels of noise, light, and air pollution. One theory is that they have become habituated to the sights and sounds of the city over time. Another is that they are attracted to certain land-based activities, such as anglers discarding fish carcasses.
Knowing that sharks may be lingering near shore, Hammerschlag advises beachgoers to avoid swimming at times of low visibility and in areas where people are fishing. He also warned that sharks could mistake shiny jewelry for a fish.
But given the rarity of shark attacks, Hammerschlag's main concern from his study is for the sharks themselves, who face threats from fishermen and polluted shorelines.
"I would say this news is probably worse for the sharks than it is for us humans," he smiled.
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