Sharks getting closer to crowded beaches than you might think, study warns

MIAMI — A new study is giving new meaning to the phrase “this city would eat you alive.” Scientists from the University of Miami say sharks are not avoiding the local shoreline. Instead, these predators are spending plenty of time quite close to the sights and sounds of the city.

On a global scale, the world’s coastlines are urbanizing at a rapid rate. So how is that impacting local aquatic life? Researchers decided to investigate by tracking the movements of three shark species on or around the Miami shoreline. This included the bull, nurse, and great hammerhead.

Considering the loud noises, chemicals, and bright lights, the research team fully expected the sharks to avoid South Beach like a bad habit. That’s not what they saw.

“Few studies have investigated the movements of ocean predators in relation to urbanization, but since other studies have shown that land predators are urban avoiders, we expected sharks to be too,” says lead study author Neil Hammerschlag, director of the UM Shark Research and Conservation Program, in a university release. “We were surprised to find that the sharks we tracked spent so much time near the lights and sounds of the busy city, often close to shore, no matter the time of day.”

Plenty of animals, like pigeons or raccoons, thrive in cities. These “urban explorers” usually eat human garbage as food. Meanwhile, “urban adaptors” spend some time in urban areas, but still largely rely on the great outdoors. On the other end of the spectrum, we find most land-based predators like wolves. These animals, called “urban avoiders,” want nothing to do with civilization.

Study authors hypothesized that sharks are urban avoiders, but ultimately conclude they act much more like urban adaptors.

sharks closer to the city
Researchers release an acoustically tagged nurse shark into waters off Miami, Florida, to investigate shark residency patterns in relation to coastal urbanization. (CREDIT: Robbie Roemer)

What’s attracting so many sharks to busy shorelines?

Study authors speculate it may have something to do with the discarding of fish carcasses by various local businesses and fishermen.

Obviously, no one wants to go for a swim in the ocean and see a fin heading toward them. However, close proximity to humans may represent just as much of a threat to sharks as the other way around.

“By spending so much time close to shore, sharks are at risk of exposure to toxic pollutants as well as fishing, which could impact their health and survival,” Hammerschlag explains.

The study is published in the journal Marine Ecology Progress Series.

Comments

  1. I have lived in South Florida since the 70’s living on or walkable to the beach some of those years. I surf,snorkel and fish. Nothing has changed. The beach is still the same, the same roads flood as before and the sharks are still in the surf

  2. A lot more grease sheen on the beach waters lately, especially on Memorial Day and other holidays, attracting more toothy critters.

  3. It doesn’t take a rocket scientist to know that the beach is like a shark buffet. Just like our buffets, the food is only a C at best, but there Is more than enough to stuff yourself.

  4. want to catch a bullshark? follow the bait schools
    want to catch a great hammerhead? follow the tarpon schools
    want to catch a nurse shark? follow the lobster pods

    The conclusion about fish carcasses is ridiculous since 3 of the biggest boat launches are in Biscayne Bay well south of Miami proper and the ping data is near non existent at these three launches.

    This study completely ignores the factors of why the sharks are there and it has nothing to do with people in the water or proximity to populations of people. If they had done this study on the opposite coast (Flamingo Bay Everglades National Park), they would have found concentrations of all of these species similarly at passes and channels at the same times of year. And lack of concentration of each of these species in large barren bays.

  5. They did not mention that the likelihood is still relatively low, full moon or not.
    Sharks do not hunt people. Most of the time, if the do bite a human, its one and done. We are not on their preference list for dinner.

  6. I’m in the water everyday metal detecting. From Jacksonville to Pensacola mostly in south Florida. Sharks like easy food sources. Nothing has changed! Sharks don’t like people. Has shark bites increased? No. Obviously with more people in the water there will be more encounters.

  7. My thoughts are the same with shark’s & gators & anything else could eat me no matter what scientists say….I’m steering clear of their area & swim in my backyard pool my time on earth is limited…bad enough we have to deal with people killing people judicial system needs to start dealing with getting rid of the harden criminals not just give them life or reducing their sentences..

  8. THERES SHARKS IN THE OCEAN WOW I NEVWR KNEW THAT (INSERT EYE ROLL HERE)
    sharks sent a threat to man
    Other way around for the
    few people killed by sharks every year MILLIONS of sharks are killed by humans and for no good reason
    You are entering THERE domain not the other way around when you are entering the ocean YOU know that YOU are taking the risk of something happening so take responsibility for it shark don’t need to die because of human stupidity

  9. I’ve encounter bull and nurse sharks many times and are only 3 to 6 feet from the shore line with water under my knees here at highland beach between Boca and Delray, I would not advise to let children alone, we spend every summer here since 2005, my two daughters always swim when they were 8 careless, but now I’m more careful with my 6 year old , I’m seeing more presence now than what I sawed 15 years ago. It’s a fact and I’ve videos

Leave a Reply

Your email address will not be published.