More than 800 loggerhead nests found on Sanibel, Captiva
Despite some bad weather, this year’s sea turtle nesting season was successful with more than 23,000 hatchlings.
Kelly Sloan, SCCF sea turtle program coordinator, said this year 826 loggerhead nests were found on Sanibel and Captiva combined. One hundred and seventy four nests were east of Tarpon Bay, 460 nests were west of Tarpon Bay and 192 were dug on Captiva.
Although the west side of Sanibel had the most in high density nesting, the east end is catching up.
“Historically over the last 20 years the average number of nests laid were 38 nests per season on the east end and this year we had 174,” Sloan said.
This year there were also two green sea turtle nests on Sanibel.
“We had a record nesting season for greens last year,” Sloan said with 26 nests. “They exhibit really strong biannual nesting patterns. We will have a great year and then a low year and that is state wide, so this year is just a low year for the greens.”
She said they had an awesome season even with the two storms impacting the island.
“That is the natural part of the sea turtles ecology. They have adapted a strategy to where each female lays more than one nest, three to five nests a season in hopes that at least one nest will be successful,” she said, adding the females will come ashore 10 to 14 days between nests.
About one in 1,000 hatchlings make it to adulthood. The female loggerheads take about a year or two off between nesting season to gain their strength again.
Sloan said the storm produced winds that came from the south causing high tides to be pushed ashore with the water reaching the dunes on some of the beaches. She said they lost 57 nests on Sanibel and 24 on Captiva.
“That means they completely washed away, but a lot of the other nests sat completely under water for an extended period of time,” Sloan said. “But we have seen a lot of hatchlings since the storms. We didn’t loose all of the nests.”
As of Friday, Sept. 23, a total of 23,017 hatchlings have emerged on the beaches, compared to 26,727 last year.
Ninety-three nests still had not hatched, which was a good sign after two storms. Sloan said all of the nests typically hatch by the end of October, but this year, she said they could see some hatch going into November.
The success in nesting was also due to the coyote deprivation being down largely from the volunteers screening the nests. Sloan said they did see a few instances where coyote tracks were spotted near the nest and then going away from the nests because of the screening.
“In order to screen a nest we have to find the location of the egg chamber. The volunteers are really good at it. I think close to 90 percent of them were screened,” she said of the nests this year.
This year between 110 and 120 volunteers provide a helping hand during the season. Daytime intern Chelsea Petrik and Technician Brant Quirk-Royal were also instrumental in making this season run smoothly.
A highlight of this season for Sloan occurred on the last night of the new tagging project SCCF began this year. She said they were tagging a female that was nesting and a nest right behind her, about 10 feet away, started hatching at the same time she was nesting.
“It was one of the neatest experiences. It is really hard to catch them while they are hatching because there is such a large range in the incubation that it could happen and also it happens really quickly,” Sloan said. “You really have to get lucky.”
The tagging program implemented this year through a permit consisted of a nighttime crew of two people – Andrew Glinsky and Jennifer Gooch – who patrolled the beaches every night from Monday through Friday from sundown to sunrise looking for nesting sea turtles.
When they encountered a turtle they placed medal tags with unique numbers on the flippers, as well as a microchip the size of a grain of rice. They also collected measurements of the turtle’s size and GPS coordinates of where they laid their nest.
When the nest hatches, the volunteers collect additional data of how successful the nest was.
The tagging program had much success this year, according to Sloan.
“It was more successful than any of us imagined,” she said. “Between May 1 and the end of July, they encountered 231 nesting females. I only ordered supplies for 100 thinking that was optimistic, so 231 was really amazing.”
Out of those 231 there were 154 unique individuals, meaning they saw some of the females multiple times.
One of the female turtles, which was first tagged in 2014, was seen 10 times this summer, many of which were false crawls. She only laid between one and 10 eggs when coming ashore, which Sloan said was an interesting find because female loggerheads typically lay a clutch of 110 eggs.
Another turtle that was originally tagged 23 years ago on Sanibel was also recorded. Sloan said she was nesting just three miles away from where she was originally seen in 1993.
Another female turtle that was tagged laid three nests, one was completely washed away by the storm and another produced more than 100 hatchlings.
“We are still analyzing the results. Hopefully by the end of the month we will have more data to share,” she said.
A positive impact the nighttime tagging crew patrolling the beaches resulted in the decrease of lights on the beaches.
“They did a really good job of having conversations with beachgoers that had flashlights on and provided red filters. I got to watch them interact with people. They were so excited to help the sea turtles and more often than not they were more than willing to use the red filters,” Sloan said, adding that she was under the impression that there was a decrease in the disorientation rate this year.
Sloan encourages individuals to keep the beaches clean with no trash and furniture, filling in holes at the end of the day and keeping lights out during sea turtle season May through October.