Bottlenose dolphins — those free spirits of the waves — are suffering from close encounters with humans.
At least four dolphins from Sarasota Bay's resident colony were struck by boats this summer, a new record. One calf is presumed dead.
In the Panhandle, epicenter of "swim with the dolphins'' tours, illegal feeding has trained generations of dolphins to associate boats with free meals.
Propeller scars illustrate the consequences, as do occasional brutalities from fishermen tired of dolphins stealing their catch. In June, one adult died with a screwdriver rammed through its skull.
In Nokomis, a dolphin dubbed Beggar has turned a narrow stretch of intercoastal waterway into his personal banquet, popping up to solicit treats from every passing boat. His crotchety nature draws little distinction between pinfish and fingers. His documented bite count now stands at 33.
"These animals are becoming habituated to being fed,'' said Stacy Horstman, dolphin conservation coordinator at the National Marine Fisheries Service. "Dolphins are social and learn from each other. Babies may not learn to hunt on their own.''
Prop scars and hooks
Mote Marine Laboratory has tracked dolphins in greater Sarasota Bay for four decades. When the Deepwater Horizon oil spill threatened dolphins off Mississippi and Louisiana, Mote data provided the baseline guide for healthy stocks.
A dolphin can live 60 years, with learned behavior passing down from mother to calf. One important lesson: avoiding boat propellers, said Randy Wells, scientist with the Chicago Zoological Society based at Mote. Until they figure it out, calves are particularly susceptible to boat strikes.
Greater Sarasota Bay's 160 resident dolphins are still recovering from a devastating Red Tide in 2005, when the population stood at 175. About 90 percent of the dolphins' natural prey died off.
With hunger trumping fear, dolphins turned to fishing boats and piers, as anglers would throw back undersized fish. Some would even strip bait and fish right off the line.
Some anglers grew angry, but others started throwing fish to dolphins. Tourists on fishing piers joined in. Despite brochures and warnings that feeding is illegal, it continues to spread, Wells said.
As a result, researchers are finding more dolphins with fishing line wrapped around fins and torsos. Necropsies of stranded dolphins often show hooks in stomachs.
"You find a lure in the esophagus or a growing calf with fishing line cutting into its body," said Horstman.
This summer, the Sarasota researchers discovered four dolphins with fresh scar marks from boat propellers. One calf that lost a chunk of dorsal fin no longer swims with its mother and is assumed to be dead.
"Most people know that manatees are hit by boats. But they figure that a dolphin is too nimble,'' Wells said. "Not true.''
This summer's boat strike rate "is higher than any year in our 42-year history,'' Wells said. "I don't want to be alarmist. It could just be random statistics. But it is unusual enough that we are trying to find out why.''
Keep up with Tampa Bay’s top headlines
Subscribe to our free DayStarter newsletter
You’re all signed up!
Want more of our free, weekly newsletters in your inbox? Let’s get started.Explore all your options
The four dolphins were not known for deliberately hanging around humans, so the prop scars might not trace directly back to illegal feeding. Natural habits also offer a possible explanation for two of the strikes.
A dolphin that researchers have dubbed Pi, 17, comes from a family that, for whatever reason, typically feeds in grass flats. The water is just 4 feet deep or less, which leaves no room to dive below a speeding boat. Pi's mother had her fin sliced up in 1996. A sister died of a boat strike in 2005.
Pi is part of a "bonded male pair'' with Noah, 16. Male bonding is a common trait among bottlenose, and actually encourages reproduction, DNA tests show. The pair will shadow a female during reproductive periods and fight off other males.
Noah is not known as a shallow water feeder, but he goes where Pi goes. In July, both showed up with fresh prop scars. Noah's gashes were so deep, researchers feared he would not survive.
"But we saw him recently,'' Wells said, "and the wounds seem to be healing and his behavior is normal.''
Swims with dolphins
Regulators recommend that people stay at least 50 yards away from wild dolphins to avoid altering natural behavior.
It's way too late for that in Panama City. The scene there resembles Yellowstone National Park back when tourists laid sandwiches on car roofs to attract photogenic grizzlies.
Personal watercraft and boats gather in the bay or along the beach and dolphins quickly swoop in. YouTube videos show delighted kids jumping in to pet them. Some people feed the dolphins; others dangle objects to tease them up to the boat.
"They sit with their heads up and beg,'' said Russ Rector, a former dolphin trainer who now lobbies against human-animal interactions. "They will stick around about 15 or 20 seconds and if you don't feed them, they will go on to the next boat. Then boats pursue them.''
Wild dolphins do not naturally seek out humans. The Panama City melee began decades ago when "swim with the dolphins'' tour operators began feeding them, said Stan Kirkland, spokesman for the Florida Fish and Wildlife Conservation Commission.
Locals in their own boats joined in. One animal taught another and now begging dolphins have become a lucrative part of the tourism economy.
One poorly punctuated YouTube posting touched on the dolphin-propeller danger.: "It was pretty awesome we got to ride jet skies out and jump off to swim with dolphins i got to touch it. Its really slimy and sad if you look closely you will see all the scars and tags on it. It was an amazing experience.''
Worse than scars are occasionally lethal encounters with fishermen. Dolphins that don't fear boats sometimes stalk anglers, stealing or spoiling their catch. Game fish take off when they sense a nearby dolphin.
In the last few years, two fishermen have been prosecuted for shooting at dolphins, and a third for throwing a pipe bomb.
This summer a dolphin showed up along the Florida-Alabama border with a screwdriver sticking into its head. It died a few days later.
Regulators have made spotty attempts to crack down on dolphin feeding. Two tour operators in the Panhandle and one in Cape Coral were slapped this summer with $5,000 citations.
The National Marine Fisheries Service surveyed Panama City residents, visitors and businesses in 2011 and found that many did not know that dolphin feeding is illegal. And many who did know the law considered feeding harmless.
The visitors who said they were very interested in protecting wild dolphins were also most likely to want to swim with them and touch them.
Biting the hand
No one knows how Beggar lost his fear of boats, but he has plied Venice Inlet for handouts for decades. A few minor scars dot his back but he demonstrates an uncanny ability to swim inches from propellers without getting hit.
Others are not so lucky.
A young dolphin that shadowed Beggar a few years ago showed up dead with severe prop scars. His emaciated body was wrapped in fishing line. Hooks floated in his stomach.
Those who think dolphins enjoy human interactions have not met Beggar.
In a 2006 report, researchers documented that Beggar bit 18 people over 78 days.
In 2001, Beggar dragged a Sarasota nurse under water when she swam with him.
"I felt this jaw grab my buttocks and pull me under,'' she told CBS News. She needed 50 stitches and one bite "went all the way down to the bone.''
Last year, Sarasota researchers monitored Beggar intermittently over four months and documented nine more bites.
Regulators have not considered killing Beggar, said Laura Engelby, marine mammal branch chief for the fisheries service.
"If people would leave him alone,'' she said, "he would not have dangerous interactions and would resume a normal life.''
Contact Stephen Nohlgren at firstname.lastname@example.org.