SCCF’s turtle tagging helps protect them
SCCF began a new sea turtle tagging project this nesting season that has resulted in eight sea turtles so far this season as of the middle of last week that will help them collect additional data to understand them.
Kelly Sloan, SCCF sea turtle program coordinator, said the sea turtle monitoring on Sanibel started in the 1950s by Charles LeBuff and his group before it was transferred to SCCF in 1992. She said it is one of the longest sea turtle beach monitoring programs in the country.
“We have all the data since 1992 and some of it beforehand, which is really helpful because sea turtles are such long lived species. It’s really natural to see ups and downs in the nest counting from year to year, so having that long term data is very valuable,” Sloan said.
Sea turtle nesting is examined on a statewide basis. The data collected has shown that green nesting has increased over the past few years and leatherback numbers are also increasing. The loggerhead nesting is a complicated trend and state officials do not quite know what is going on yet. With a few more years of data, the loggerhead nesting will provide more insight.
Although nests have historically been found on the west end of the island, west of Tarpon Bay Road, SCCF is starting to find nests on the east end of the island as well.
“We have had two record years in a row on the east end,” Sloan said. “It seems they like that habitat now.”
Last year was a record year with 522 nests on Sanibel and 133 nests on Captiva.
The east end had an average of 39 nests per year. Last year they had 120 and the year before they counted 110 nests.
The west end had a record year as well.
“This year we are starting off slower, but it is comparable and we are right on par with the 2014 season, which was a record year at the time,” Sloan said.
The loggerhead sea turtles begin coming ashore late April and continue through the end of July, early August. The green sea turtles nests tend to start in June. The nests start hatching two months after laid.
SCCF began a new program this year by hiring two researchers that patrol the beach four or five nights a week looking for nesting sea turtles. The SCCF project is permitted for 2016 through a special permit with FWC to do the tagging.
She said Mote Marine Lab and the Conservancy of Southwest Florida have both been doing the projects for a long time providing long term data. Sloan said is is possible that they get some recaptures from their beaches and learn more about the population structure.
If the researchers find a sea turtle that is nesting they stand back and wait for her to completely finish nesting her eggs. Once completed, they will measure her and apply metal flipper tags on each of the front flippers and then insert a tag, which is very similar to a micro chip.
“They have encountered, as of last night (Wednesday, May 18), eight sea turtles,” Sloan said. “We are hoping that the data we collect from this project will help us guide conservation efforts and better protect nesting habitat on Sanibel.”
She said the project will also help them understand the threats the sea turtles are facing.
“You can learn so much from these projects,” she said. “One of the big questions, this isn’t one of our specific questions, but most beaches don’t have nighttime tagging projects, so all you know at the end of the season is how many nests are laid. You don’t know how many females are in the population. Each female will lay multiple nests throughout the season with about three to five nests. Having information on individual females you can learn more about how many nests they are laying during season on our beach.”
Every two weeks on average, the turtles will come ashore and lay another clutch. Sloan said the turtles do not nest every year because they take a season off eating and building their energy.
The sea turtles typically lay 110 eggs on the island at a time. Sloan said the sea turtles uses this strategy because not all of them survive to adulthood. Only one in a 1,000 survive.
The eggs hatch between 45 to 60 days on the beaches of Sanibel and Captiva. She said the incubation period depends on the temperature of the nest.
There have been some added bonuses with the tagging project. Sloan said they have been able to further educate people about sea turtle friendly lighting. In addition, the researchers presence on the beach may be enough to discourage coyotes traveling on the sand because they are naturally fearful of humans.
Last year was the first year they started screening as many nests as possible, which was really effective. Sloan said their depredation rate went from 32 percent to 15 percent last year. She said the loggerhead plan suggests that they get the number down to 10 percent, which is their goal.
SCCF has more than 100 volunteers that help with nest protection on the islands during the nesting season, which officially began May 1. Some of the volunteers walk the beach in the morning looking for crawls, which are then called in to a volunteer that has more training.
This year SCCF started keeping track of how much garbage volunteers pick up while walking the beaches. In a months time, 240 gallons of garbage has been collected on five miles of beach on the east side of the island.
“We see all kinds of plastic left behind – beach toys, a lot of straws – cans, bottles, sometimes we see monofilament washed up from fishing. Really we see everything,” Sloan said. “There is a lot of trash in the sea right now and it is having an impact on all sea life. It makes me really proud to be apart of a program that is helping with that issue.”
The volunteers also fill in holes that were left on the beach during the day. Sloan said the holes are filled to help protect the adult sea turtles from falling into them, becoming trapped, or injured. She said they also help with educating individuals about not leaving behind furniture on the beach.
“Unless you focus on the beach as a habitat for animals, you really don’t focus on that type of thing,” Sloan said about garbage, holes and furniture.
She said individuals can have fun during the day, but she encourages them at the end of the day to fill holes and knock down sandcastles that could be an obstruction.
One of the biggest issues in Florida concerning sea turtle nesting season is lights. Although Sanibel adopted a Dark Sky ordinance, Sloan said they see a lot of people with flashlights on the beach shelling at night.
“A really easy way to make that sea turtle friendly is to put a red filter on top, or to use a red headlamp, or red flashlight,” she said. “They are attracted to a white light because when they first hatch they go to the brightest point on the beach, which is historically the reflection of the moon off the sea. So they are really attracted to the white light because that is how they find the sea. But, the red light they are not attracted to.”
Sloan said they have red filter paper that she is happy to distribute to people.
The more they know about sea turtles the better they can protect them, she said.
Follow Meghan @IslanderMeghan on Twitter.