CNN

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A new University of Miami study has found that sharks are frequent visitors to water near crowded cities. Dr Neil Hammerschlag 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.