Summer boat traffic has striking impact on marine life

The summer holidays bring increased boating activity to the Sarasota area, and with this increased activity comes marine animal injuries and deaths due to boat strikes.

“Around every holiday weekend, there is increased boat traffic on water, especially during the holidays associated with more libations, like Memorial Day, Fourth of July and Labor Day,” said Rebeccah Hazelkorn, staff biologist at Mote Marine Laboratory’s Stranding Investigations Program. “It’s a numbers game. Because there are more boats, we frequently get calls about boats striking these animals.”

On July 5 and 6, three loggerhead and one Kemp’s ridley sea turtles were recovered dead from boat strikes in Sarasota County waters.

“It’s unfortunate these busy boating times coincide with turtle nesting season,” Hazelkorn said. “Turtles can live through a lot, but boats can be too much. When a turtle has to breathe, a turtle has to breathe. They’re just at the wrong place at the wrong time.”

Hazelkorn estimates that 30% of sea turtles have suffered from some form of human interaction, which includes entanglement and ingestion of fishing lines in addition to boat strikes. This happens more frequently this time of year because turtles are swimming just offshore to mate, and females are venturing onto land to nest.

Mote also deals with boat collisions involving dolphins, manatees and even whales. Both dolphins and manatees in the area frequent shallow waters and may be unable to dive below an approaching boat.

In 80% of calls dealing with boat strikes, the animal is already dead.

“It’s very rare we get a call that they’re alive, that it’s breathing,” Hazelkorn said. “It’s rare, but we’ve had a couple of success stories. It’s not always a death story.”

In late June, a boat propeller struck a 17-year-old male Sarasota dolphin’s dorsal fin. The dolphin remains in the wild and seems to be healing. Mote scientists continue to monitor him. The dolphin is known as a resident “bad boy,” due to his lack of fear about approaching humans and boats and reputation for stealing bait.

“Dolphins are much quicker than turtles, but sometimes they can’t even get away fast enough,” Hazelkorn said. “Dolphins are remarkable, and some have sustained much worse than this guy. He seems to be back to his old, bad ways, which we see as a sign of him healing.”

An estimated 5% of Sarasota Bay resident dolphins show evidence of boat strikes, and a manatee without boat strike scars is rare.

“The way manatees are identified here is by their propeller strike scars on their back,” Hazelkorn said. “Their scar markings are how we tell them apart. Manatee strikes happen pretty frequently. They have a lot of healed scars.”

Although Hazelkorn knows boat strikes are inevitable, she encourages boaters to become more aware of their surroundings.

“An accident is an accident, but people need to pay attention to the waters and know that’s the animal’s home, not theirs,” Hazelkorn said. “We know you’re going to go out on the water and have a good time; just be careful. Those guys have a hard life from the moment they’re an egg or baby to adulthood. Why not make it a little bit easier for them?”