ST. LOUIS – The world is rapidly becoming more urban and coastal cities are growing even more quickly. So, what is the impact on marine ecosystems? One study found a surprising result that has some bite.

A new study out of the University of Miami says sharks are not getting scared away from packed beaches.

“I thought this study was interesting to them not reacting or swimming away from crowds,” said Tami Brown, the executive director of the Saint Louis Aquarium. “So, I think that’s a new layer for all of us to be aware of as we enjoy those beach vacations.”

Scientists tracked hammerheads, bull sharks, and nurse sharks off the Miami, Florida, coast. They expected the predators to avoid the noisy, densely populated coastline. But they found the opposite: sharks spending plenty of time close to shore.

“I think they’ve started to adapt to humans being in their habitats,” said Brown. “And it doesn’t scare them quite as much.”

The study speculates it may have something to do with fish carcasses discarded by local fishermen and an aquarium.

“Sharks are opportunistic feeders. They don’t really want to spend all that energy to hunt,” said Brown.”

So, yes, if you are headed to the beach, you might see a shark.

“You will see the fin. You will see some feeding behavior. Dawn and dusk are particularly active times for a shark. And, so, you just have to be aware,” said Brown.

But don’t panic.

“The chances of being killed by a shark are less than being killed by a cow,” Brown explained. “I think people have built up a natural fear of these sharks, and they are certainly predators, but we are not a natural food source for a shark. They are not going to naturally want to hunt people.”

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