Earlier this summer, in the Gulf waters near the Florida-Alabama border, somebody stabbed a screwdriver into the head of a bottlenose dolphin.

Sightings of the injured mammal occurred for a couple of days until it turned up dead in Perdido Bay. The crime, which remains unsolved, is notable for more than its extreme cruelty.

Years ago it would have been unusual for a human with a weapon in his hand to get near enough to wound a wild dolphin. That was before people began following and illegally feeding the animals, a practice recklessly adopted by a few tour-boat captains in the Panama City area.

The result was to train communities of dolphins to be not just lazy but dependent on handouts for survival. Instead of teaching their offspring how to hunt schools of baitfish, momma dolphins taught the little ones to wait for boatloads of tourists bearing buckets of chum.

Dolphins are smart and opportunistic. When the tour boats weren’t around they started bothering commercial fishermen, who with their paychecks on the line didn’t regard the voracious acrobats as fondly as visitors did.

According to the National Oceanic and Atmospheric Administration, the government in recent years has prosecuted three fishermen for attacking dolphins. Guns are the favored method, and in one case a pipe-bomb was thrown.

The screwdriver killing is a first. Experts believe the mortally wounded dolphin came from a place near Orange Beach, Alabama, where feeding the protected marine mammals has become popular.

In most places you seldom hear of a dolphin being struck by a boat propeller. The adult specimens always teach the calves how to keep a safe distance from the engines — you can see these lessons in progress when a pod comes together in your wake.

Likewise, it’s uncommon in most waters for a dolphin to take a bait on a fishing line. They know better than to bite anything with a piece of barbed steel in it.

Except when they’ve lost their natural wariness of humans.

Increasingly, necropsies on dead dolphins reveal fish hooks in their stomachs, or monofilament line tangled around their fins.

Stephen Nohlgren of the St. Petersburg Times recently wrote of the troubles facing a resident group in Sarasota Bay. This summer, four of the dolphins were struck by boats. One was a calf that later disappeared from the pod and is presumed to have died.

Local marine scientists haven’t seen such a spate of deaths in 42 years of research. The animals hit by vessels hadn’t been known to follow humans for food.

However, dolphin feeding did become more common in the region after a Red Tide in 2005 wiped out many small prey fish. In hunger, some dolphins learned to mooch around piers and charter boats.

Nohlgren tells the story of an old-timer, the aptly named Beggar, who works a busy section of the Intracoastal Waterway in Nokomis, between Sarasota and Venice. Beggar accosts passing boaters who think he’s adorable, and obligingly toss goodies from the baitwell.

So far he’s bitten 33 of his benefactors.

It’s been illegal to feed wild dolphins since 1991 but, despite the well-publicized penalties (jail time and fines up to $20,000), state and federal authorities have had trouble stopping it.

The Panama City area remains the epicenter. Stacey Horstman, bottlenose dolphin conservation coordinator for NOAA Fisheries, says sometimes a single dolphin will be surrounded by 30 to 50 humans in the water. “A pretty tough scene,” she said.

The evidence is plentiful on YouTube, where partiers with submersible cameras like to share their cross-species encounters. The dolphins in these videos behave more like raccoons at a garbage dump.

A few months ago, a tour operator in Cape Coral and two more in the Panhandle got fined $5,000 for feeding dolphins. Vendors in Panama City continue to promote swim-with-the-dolphin tours while publicly saying that no feeding is allowed.

What they don’t say is that the only reason any dolphin swims with a human is to sponge a handout. Contrary to myth, Flipper has no interest whatsoever in being your friend, unless the payoff is a juicy sardine.

Still the congenitally clueless — tourists and locals alike — continue to flop into the Gulf and mess with these phenomenal creatures, dooming them to a future of begging, sloth and worse.

A dolphin that swims close enough to take a treat from your fingers is also close enough to be stabbed by a scumbag with a screwdriver.