Remember what happens when the shark shows up in “Jaws”?

In a classic case of government ineptitude, the mayor of Amity refuses to close the beaches and defies the warnings of his own police chief and an oceanographer. He's more worried about tourism dollars than public safety, a stance he soon will regret.

Now, it seems, the world has gone topsy-turvy.

On Long Island, county government officials and park police grew alarmed last summer by shark sightings close to shore. They have taken an aggressive stance to protect bathers, investing in staff training, Jet Ski patrols and drone and helicopter surveillance.

The experts, however, are nonchalant. A field scientist was quoted in the New York Times as saying that sharks are not interested in swimmers, and the “danger to people is infinitesimal.”

Don't tell that to the lifeguard on Fire Island who, on the same day the biologist's quote was printed, was attacked by a shark.

In an irony worthy of the movie, the lifeguard was playing a shark-attack victim during a training exercise off Smith Point Beach when a shark bit his chest and hand. He is recovering.

In 2020, a 63-year-old woman swimming off the coast of Maine was bitten and died of her injuries. In 2018, a 26-year-old surfer was attacked and killed by a shark off Wellfleet in Cape Cod.

As warming ocean waters bring more seals to the New England coast, sightings of their predators, great white sharks, have grown more common. This increases the likelihood of encounters with humans, especially in the summer.

The chances of a shark attacking a human may be slim, but that doesn't mean we should take no precautions.

Long Island officials are to be commended for taking proactive steps to keep swimmers and surfers safe. Similar measures are being taken on Cape Cod, where the Massachusetts Division of Marine Fisheries identified more than 500 white sharks between 2014 and 2018.

A system of buoys off Wellfleet alerts lifeguards if a tagged shark passes nearby. But this only works if the shark has been tagged. State police also have done shark surveillance by helicopter, with a scientist in tow.

None of these steps harm wildlife; they are observational. Swimmers also can take precautions to keep themselves safe, such as avoiding seals and schools of fish that attract sharks.

Wildlife biologists who scoff at the dangers may find themselves in the position of Mayor Larry Vaughn in “Jaws,” watching helplessly as the shark shows up and the waters empty. We would do well to learn the lesson of that iconic film, which is that official incompetence and hubris can have dire consequences.