More than a century ago, the U.S. Fisheries Commission recommended a ban in Florida on sea turtle egg harvest to prevent their “extermination,” according to a history from the Sea Turtle Conservancy.
Since then, an understanding of sea turtles and how to protect them in Florida, including Anna Maria Island, has continued to evolve.
During nesting season, which is May 1-Oct. 31, female sea turtles come to the shores of Anna Maria Island to dig their deep nests in the sand and deposit their eggs. The eggs incubate in the sand and then hatchlings — 100 or so at a time — make their way to the Gulf of Mexico.
Public information campaigns usually focus on what people can do to promote the turtles’ survival but what else do we know about sea turtles? And what have conservation efforts looked like in the past?
The Islander spoke April 10 to Dr. Jake Lasala, head of the Sea Turtle Conservation & Research Team at Mote Marine Laboratory, to learn more about them.
“Sea turtles are a charismatic megafauna. People really like them but we don’t know a whole lot about them,” Lasala said.
Loggerheads and greens, two frequenters of the Anna Maria Island shoreline, get their names from their dietary preferences. Sea turtles can range from vegetarian to voracious carnivore.
“Loggerheads are called ‘loggerheads’ because their heads are big, and the reason why their heads are big is because they need to have the jaw force to crunch down on crustaceans and mollusks and things like that,” Lasala said. “Green sea turtles are called greens because their body fat is green.”
Compared to loggerheads, greens are more likely to eat algae and seagrass.
Meanwhile, leatherbacks, a more elusive species to the area, prefer gelatinous prey, such as jellyfish.
This is a reason why it is important to prevent plastic litter: “Not only sea turtles but other animals can see it as … food,” Lasala said.
Lasala, who studies sea turtle populations through the lens of paternity, also identified reproductive and nesting behavior as a most engaging part of his work.
Many people are probably familiar with genotypic sex determination, which is when chromosomes determine gender, like in humans.
However, for sea turtles, sex depends on the environment.
“At a certain temperature of incubation, individuals become male or female,” Lasala said. “For loggerheads, this temperature is 29 degrees Celsius.”
As temperatures grow due to global warming, there is a risk of declining male sea turtle populations and lower hatchling survival rates in general, as nests overheat.
Since Mote began collecting data in 1982, indications have shown that sea turtle populations have increased in Sarasota County.
“That’s not to say we have a skyrocketing population globally,” Lasala said. “If you talk to someone down in Costa Rica, they are going to tell you a very different story.”
Protecting the sea turtle species in Florida and elsewhere is essential, he said, because they are keystone species.
“A keystone species, if they disappeared, would have a drastic impact on the ecosystem further down the road,” Lasala said. “And one of the conversations we’re having about leatherbacks in particular is that their population has started to decline, and we’re seeing blooms of jellyfish in different parts of the ocean, and that is possibly connected to each other.”
On Anna Maria Island, the history of sea turtle preservation efforts goes back at least to 1982, when a turtle watch program began to evolve.
For some time, turtle watch occupied what once was the city “ice house,” now the Anna Maria Island Historical Society building in Anna Maria before the society received permission from the city in 1992 to renovate the “Turtle House,” as it was called, according to a BeachComber story by the late Pat Copeland, one of the historical society founders and a journalist who also worked for various newspapers.
During its early history, turtle watch members would raise hatchlings in vats of water, according to archival material by Carolyne Norwood, also a founder of AMIHS.
Sea turtle biology was less understood then and people had the misconception that removing hatchlings from their nests into a controlled environment was the best way to protect them.
In the early 1990s, a group of sea turtle helpers maintained two hatcheries, one on the beach near Willow Avenue in Anna Maria and one at Coquina Beach in Bradenton Beach.
The team of volunteers removed nests from the location on the beach where they were laid to the screened-in hatchery for protection.
As the nests showed signs of hatching, the team would alert friends and others via a “coconut telegraph” and people would appear at the appointed location to watch the release of sometimes multiple nests.
The state put a halt to the hatcheries and denied the group their permit, but by 1997, turtle watch was renewed and became a nonprofit.
The data on nesting numbers goes back to 1982, according to Kristen Mazzarella, its current director.
That year — 12 years after the first Earth Day — the group recorded 23 nests.
Currently, that number has increased to between 400 and 500 a season, Mazzarella said.
Looking back at the progress, we can see our understanding and protection of sea turtles and their habitat grow with each Earth Day celebration.
Click to read about the history of sea turtle policy in Florida at the Sea Turtle Conservancy site.
