Concern about sea turtle disorientation increases with lack of dunes

Walking along Longboat Key’s beaches, some parts of the beach are flatter. In some areas, beachgoers can see through to Gulf of Mexico Drive. In this upcoming nesting season, sea turtles will experience the same. 

Those differences in the beach is concerning, said Melissa Macksey, a senior biologist with Mote Marine Laboratory & Aquarium’s Sea Turtle Conservation & Research team. 

Dunes are important not only for keeping the beach in place and protecting property, but also for acting as a natural light barrier for sea turtles. 

“They shadow the beach and they block a lot of these lights that cause disorientations," Macksey said. “Without the dunes, there are going to be more exposed places.”

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Disorientations occur when adult or hatchling sea turtles become confused with artificial light visible from the beach. The turtles rely on the natural moonlight to find the ocean again. 

Chapter 100 of Longboat Key’s town code, “Marine Turtle Protection,” states that all lights visible from the beach must use turtle-friendly bulbs or fixtures, or must be shielded or turned off.

Macksey said, without the dunes, there would be many more lights exposed where they previously were not — things like first-floor lights, hotel lobbies and pool lights. 

There is also a general loss of vegetation along the back of what used to be the dune system. This lack of vegetation is an added blow to the beach’s natural barrier. 

“I think we have to consider lights that maybe we didn’t even think about before,” Macksey said. “A lot of lights were lower, or around the side (of a property) or technically not beachfront properties, but now they’re visible from the beach.” 

Not only do the dunes block light, but they also act as a barrier for the nesting and hatchling turtles. If the turtles do become disoriented by light visible from the beach, the dune could stop them from reaching busy roads like GMD.

“If the turtles don’t have an end to the beach, how far in will they go?” Macksey said. “I am a little worried about that increasing this year in areas that were already higher risk.”

Cause for concern

Vice President of Longboat Key Turtle Watch Cyndi Seamon said residents are noticing the multi-faceted importance of dunes more than ever before. 

Dunes can do a lot for turtles — shield natural light, act as a barrier to the road and also provide another viable netting ground. But dunes also mean storm surge protection for homeowners. 

It’s because of all these reasons that Seamon said she’s heard a lot of interest in property owners wanting to conduct private dune replenishment. 

“It seems like there’s a lot of community support,” Seamon said. “People really now understand how important a healthy dune system is.”

Seamon worries about the same issues as Macksey — lights that weren’t visible before and turtles possibly entering the roadway. 

“There are spots where you can actually see the beach from the road and vice versa,” Seamon said. “If you’re walking on the beach, you can see the cars on the road where you could never see that before.”

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Seamon said she attended some condominium association meetings to try to spread the word about the importance of dunes, and the expectation that residents will need to be more cautious about sea turtle-friendly lights this year without dunes. 

“There’s going to be more lights because there’s going to be less vegetation, fewer trees and also lights that we haven’t seen across GMD,” Seamon said.

Even if all the visible lights are turtle-friendly bulbs and amber-colored, Macksey worries the increased amount of those lights could create a significant enough glow to cause problems. 

Though the official start to the sea turtle nesting season is May 1, Macksey suggested that people should start thinking about turtle-friendly lighting around mid-April. 

Nesting sea turtles often begin around this time, and with less dune shielding, she’s worried about nesting sea turtles becoming disoriented.

Photo by Bekah Horsley/Mote Marine Laboratory

“My biggest concern is the disorientation rate,” Macksey said. “There are going to be more lights visible and, even if they are turtle-friendly, there will still be more (lights) and that still creates a brighter environment.”

Seamon suggested residents start thinking about lighting even sooner than April.

She said some fixtures may take longer to set up or figure out, especially if this is the first time property owners have to use these fixtures. 

Macksey said when in doubt, make a light turtle friendly. This could mean using turtle-friendly lights, shields, blinds or turning off the lights.