9-4-2025
Hello and happy Thursday!!
At this point in the season, we have a total of 868 loggerhead nests between both islands, with 654 on Sanibel and 214 on Captiva. From these nests, 15,863 hatchlings have come from Sanibel and 5,398 have come from Captiva for a total of 21,261 hatchlings. There have been no green turtle nests laid on Captiva but 21 were laid on Sanibel, resulting in 255 green hatchlings. Taco is one of the turtles who nested on your beach and her nest hatched very successfully! She was first spotted on the island in 2018, then returned in 2021 and 2023. This year she was spotted twice on Sanibel and both interactions resulted in nests. Unfortunately, her first nest that was laid on the east end of the island was depredated a few times and the remaining eggs didn't hatch. However, the nest at Chateaux Sur Mer had 102 hatchlings emerge from the nest!
We are currently conducting an important research project to learn how red tide toxins (aka brevetoxins) affect hatchling fitness, health, and survival. Brevetoxins are neurotoxins that are produced by a dinoflagellate algae called Karenia brevis and can become extremely toxic to wildlife and people in high concentrations.
This current research is building on previous research that we completed between 2019 and 2022, where we collected 412 samples from nesting females and 276 hatchlings found dead in nests to analyze brevetoxin loads. Through this study, we were able to confirm that toxin transfer occurs from mom to hatchling, and discovered alarmingly high values in many hatchling livers. We also found that nests with higher concentrations of liver brevetoxins had lower hatch success, suggesting the toxins may impact hatchling survival.
To determine how this accumulation can impact live hatchlings, we are collecting hatchlings to do fitness tests on the beach and see how quickly they can right themselves when they are on their backs, both in the sand and in water. Self-righting is an important component of survival, as hatchlings get flipped easily on the beach by the waves in the sea. Upon completing these tests, we are measuring the turtles and taking very small blood samples to analyze the concentration of brevetoxins in their plasma and conduct a very comprehensive health analysis, all with a tiny drop of blood! We will use the data to see how concentrations of brevetoxins affect the overall fitness of the hatchlings.
Understanding the effects on the hatchling life history phase is especially important because survival during this early life stage can have a strong influence on population recovery. It is important to consider the impacts of these blooms on sea turtle health and reproduction when evaluating stressors on the population and developing management strategies. Without this information, we are only able to focus our conservation efforts on what happens on the beach during nesting, but their survival after they leave our beaches is just as important.
8-19-2025
Hello and happy Tuesday!!
Since my last update there have unfortunately been no nests laid on Chateaux Sur Mer, but there have only been 3 nests laid on the west end of Sanibel since my update. Currently there have been 18,446 loggerhead hatchlings that have emerged from nests on Sanibel and Captiva; 4,535 hatchlings being from Captiva and 13,911 from Sanibel, as well as 185 green turtle hatchlings. Of these, 678 loggerhead hatchlings and 30 green hatchlings have come from 10 nests that hatched in Chateaux Sur Mer. This number might seem small for hatches because there were a total of 32 nests laid at Chateaux Sur Mer. There are still 16 nests incubating in Chateaux Sur Mer and we are hopeful that these will boost your hatchling numbers! Also, coyote depredation has become a significant issue in the past few years, and they have completely depredated 6 of the 32 nests that may have otherwise already hatched in Chateaux Sur Mer. If you are interested in learning more about coyote depredations on the island, you can listen to this podcast where our biologists spoke about this topic .https://creators.spotify.com/pod/profile/landwaterwildlife/episodes/Coyotes--Sea-Turtle-Nest-Depredation-e36ooul/a-ac3mdtg
Some of the turtle mommas of these hatchlings include Lemon Creme, Taco, Mercury, and Olivia. Olivia is the mother of the 30 green hatchlings and was seen 3 times this year by our night team, resulting in 3 nests. The first nest she laid this year resulted in 60 hatchlings and the last one is still incubating. She was first seen in 2017 where she had 1 false crawl and 4 nests; unfortunately two were completely washed out by a major storm event, but the two that hatched resulted in 123 hatchlings and had success rates of 93% and 95%! In 2022, she was observed 4 times by the night crew, resulting in 4 nests, one of which was also washed out by a major storm event, but the other 3 produced 188 hatchlings.
Here is a loggerhead hatchling heading to the water :)
Flippers crossed fr more successful hatches!
Lizzy
8-4-2025
Happy Monday turtle friends!!
Slowly but surely, the nesting season is starting to wind down. In the last week, between both Sanibel and Captiva, there have only been 19 new nests laid. Nest hatches however have picked up significantly; we have currently inventoried over 150 nests and produced 12,458 hatchlings into the Gulf. There have been a total of 881 nests between Sanibel and Captiva, with 668 on Sanibel and 213 on Captiva. With the nesting rate slowing down, our nighttime tagging project has come to an end on July 31st, so I thought I would share some of the data they collected. There have been 316 interactions between our night team and nesting females, including 103 false crawls, 212 nests, and one crawl that was washed out by the tide before morning survey. The largest loggerhead female we encountered this year was Spring Roll, measuring 114.2 cm, who was first seen in 2024. She was seen 6 times this year, 5 times resulting in a nest and one false crawl. Two other nests have been inventoried / hatched so far, 15E had 157 eggs that did not hatch likely due to the sand being very wet, but N105W hatched very well with 120 hatchlings emerging from the nest. Her other nests are still incubating so it will be interesting to see how those do! The smallest loggerhead that was seen by our team was Rover who was first seen this year and is only 80.3 cm. She was only seen once this season, but her nest has not hatched yet. The turtle who was encountered the most times was Garlic who was first encountered in 2018, then 2020, 2021, and 10 times this year!! Her encounters resulted in 5 nests and 5 false crawls, only one of her nests is in the hatching window, however it was fully depredated by coyotes.
Since my last email there have been 3 new nests, laid by 2 new females, Cyphoma from our space year and Ginger from the spice year in 2018. This brings your total nest number to 32 and female encounters to 13. In the last two weeks two nests have been inventoried, the first was previously depredated by coyotes and unfortunately did not hatch. The second hatched, but then was depredated the same night it hatched and in that scenario we only count the hatched eggs that are still inside that nest. Because of this, we can only say that 9 hatched, but it seems likely that more hatched, we are just not able to include those in our numbers. This second nest that hatched was laid by a new turtle we found this year named Mercury, and this was the only time she was spotted on Sanibel all season. She must have really liked you guys!! So far you are at a total of 300 hatchlings of the 12,458 hatchlings that emerged on the islands. As more nests hatch I will give more detailed information on hatch success and prior years of nesting data.
Have a great week!
Lizzy
July 17, 2025
Happy Friday turtle people!
This week we are going to talk about green sea turtles, the second most common sea turtle that nests in Sanibel. Florida actually has one of the largest groups of nesting green turtles. Most of the green sea turtle nests are focused on the east coast of Florida, but the populations on the west coast are slowly increasing. Currently, there are 13 green turtle nests on Sanibel. They are the largest hard shelled sea turtle in the world, with adults typically measuring between 3 and 4 feet and weighing between 350 and 500 pounds.Similarly to the adults, green turtle hatchlings are bigger than loggerheads, and are mostly black with a white plastron (underside of shell) and white around the edges of the shell and flippers. Leatherbacks are the largest sea turtle, but as the name implies, they have a tough, leathery skin instead of a hard shell like you see with most other turtles. Green turtles are different from other sea turtles because they are primarily herbivores, eating mostly seagrasses and algae but will sometimes eat sea sponges and other invertebrates. Their name is not based on the color of their shells, but their green colored fat due to their diet. Green turtles have a bit of a later start to nesting season than loggerheads, beginning in the end of May/ June and will nest up to 7 times laying clutches of about 110 eggs each time. Same as loggerheads and all other sea turtles, the sex of the hatchlings is determined by the temperature of the sand (hot chicks cool dudes). When green turtles nest, they make a huge depression in the sand before they start laying their eggs, which is very different from the way a loggerhead nest looks. The threats that adult green turtles face are very similar to those that loggerheads and other sea turtles face, including boat strikes, entanglement in marine debris. Risks for green turtle hatchlings are also the same as loggerheads, including white light which leads to disorientations, holes in the sand, and a multitude of sea-dwelling and land-dwelling predators.
Onto some nest updates… There have been 6 new nests in Chateaux Sur Mer, for a running total of 28 total nests of the season so far. Unfortunately, none of these nests were laid by mommas that were encountered by our night team. Our night team has had a total of 11 encounters with nesting females in your neighborhood! So far 3 of your total 28 nests have hatched, resulting in 291 of the 3044 total hatchings from Sanibel. There have also been 528 hatchlings on Captiva, making a total of 3572 hatchlings between both islands. Taco is the mother of one of the nests that hatched, resulting in a total of 102 hatchlings! She was tagged on Sanibel in 2018 and that year nested 3 times, with a total of 156 hatchlings between all nests. She nested twice in 2021 for a total of 102 hatchlings, three times in 2023 when 2 of her nests were completely depredated and the third had 110 hatchlings, and in 2024 one nest with 61 hatchlings. It’s pretty cool to see how her nest this year compared to previous years!
June 25, 2025
Happy Tuesday turtle people!
We are quickly approaching hatchling season, and should be having some nests hatching in the next few weeks! This is very exciting and I thought I would take this as a chance to explain some things involving nests hatching. After an incubation period of about two months, the hatchlings begin to pip, or break out from their eggs, using a little tooth called a caruncle. They then stay in the nest for a few days to absorb any remaining yolk from the egg, so they have the strength and energy to take the long trek to the water. At the same time, the hatchlings use each other as a boost and climb on top of each other in a frenzy to get out of the nest; this is often referred to as a boil because it looks like a pot of boiling water. They emerge from the nest at night because the sand is cooler so they won’t overheat, and there are less predators than in the daytime. Emerging all at the same time also offers them extra protection from predators because there is strength in numbers. To make their way to the water, they use both the slope of the beach, and by heading toward the brightest area, which is the reflection of the night sky on the water. This is why it is so important for people to turn their lights off after nine, so the hatchlings do not get disoriented away from the water. Three days after a nest hatches, SCCF staff and permitted volunteers will dig up the nest to see its success. In doing this, we gather important information including how many eggs hatched, how many didn’t hatch or why they didn’t hatch, and to help any remaining stragglers get out of the nest. This process and data are very important so we can get information about populations, nest success, and insight on why some nests were not as successful as others.
Now for the exciting turtle updates… Chateaux Sur Mer has 7 new nests!! This brings the total number of nests laid on your beach this year to 18 nests!! With these new nests, we also had some more visitors, Queen Tut, one of our satellite tagged turtles that I will talk about next week, and Olivia, one of our green turtles. This brings the total number of females our team has encountered at Chateaux Sur Mer to 8 turtles, 7 loggerheads and 1 green. On the island as a whole we have 335 loggerhead nests, 8 green turtle nests, and 137 nests on Captiva, bringing us to 472 total nests across both islands! As mentioned above, we are quickly approaching the hatchling season, so hopefully my next email will have some inventory data and the best part of the sea turtle nesting season, cute hatchling photos!!
Cheers until next time!
Lizzy
June 6, 2025
Happy Friday Turtle Friends!!
Today I’m going to tell you about loggerheads, the most common turtle to nest on Sanibel and Florida as a whole. Florida actually is the biggest nesting beach for loggerheads in the whole world, how cool?! Loggerheads are named after their huge heads that have extremely powerful jaws, used for crushing their prey that often consists of hard shelled invertebrates. Some of these hard shelled prey items consist of whelks, conchs, crabs urchins, and horseshoe crabs. These turtles can be observed between 2.4 and 3.5 feet and can weigh between 155 to 412 pounds, with the average adult being 3 feet and weighing about 275 pounds. Female loggerheads nest about every 2-3 years and during one season, can lay 4-7 nests, with a range of about 14 days between each nest. Nests can have a range of clutch sizes between 80-120 eggs per nest. Like all sea turtles, the sex of the hatchlings are determined by the temperature of the sand (hot chicks cool dudes) with Florida producing more female hatchlings than males due to high sand temperatures. There are many threats that adult loggerheads face including white lights that lead to disorientations when nesting, beach furniture and large holes on the beach that they can get stuck in, boat strikes, change in environmental conditions and habitat, and shark predators. As I’ve mentioned in some previous emails, the nests and hatchlings are vulnerable to predators, like the coyotes in Sanibel (everything is coming full circle, remember my email about our use of cages ), as well as white light which leads them to disorient even more than the nesting females. To finish this off, some ways that you can help sea turtles is use redlights at night to prevent disorientations, make sure you fill in all holes on the beach and bring in all beach furniture to prevent them from getting stuck while nesting.
Since my last update there have been 4 new nests, bringing the current total to 11 nests! For our surveys, Sanibel Island is split into 3 sections. Chateaux Sur Mer is part of the west end section of our survey, which goes from Tarpon Bay until about the end of Bowman’s Beach. The west end currently has 138 nests, including the nests in your section, for a total of 239 nests on the whole island; Captiva has 74 nests. I also have to shout out the 3 new turtle mommas that have been identified by our night team on your beach in the last two weeks. Sportulla was first spotted in 2016 from the shell year, French Silk from 2018’s ice cream year, and Mars from this year’s space theme! This makes a total of 6 turtles encountered on the beach of Chateaux Sur Mer since our nighttime tagging has begun. If you have any suggestions for space themed turtle names please feel free to send me an email!
Unnamed jpg shows Mars body pitting in the sand. This is the beginning of the nesting process, where they remove the top, loose layer of sand, so they can dig an egg chamber that will not collapse in on itself.
Unnamed jpg 1 is Mars returning to the water after nesting.
Unnamed jpg 2 is a loggerhead hatchling that I encountered last nesting season on Don Pedro Island State Park.
Stay tuned for my next update! Have a great weekend! Lizzy
May 23, 2025
Happy Friday Turtle Friends!
Another two weeks of turtling has gone by and we have some updates. As of May 1st, our nighttime tagging team, Savannah and the night interns Megan and Taylor, have started doing their surveys. They begin shortly after it gets dark and all night they patrol back and forth from the lighthouse to the end of Bowman’s Beach, looking for nesting females. When they come across a nesting female, they wait for her to finish nesting, then they take size measurements, scan her for identification tags, and give her a name based on the theme of the year. Previous themes have included fruit, ice cream flavors, and types of shells, with the theme this year being ….. SPACE. YAY! In the event that there are no tags, they will tag her for identification purposes. SCCF uses two types of tags, an internal Passive Integrated Transponder (PIT) and an external flipper tag. An easy way to understand the difference between these tags would be to think about what we would use to identify our dogs and cats. A PIT tag is similar to a microchip and could only be found using a PIT scanner, similarly to how a pet microchip can only be detected by a veterinarian. As the name suggests, external tags are located outside the body, which can be viewed by anyone. These tags are used for many reasons: they identify the individual turtle, and allow us to track both her nesting behavior and her movement patterns. Since the programs began in 2016, and since then SCCF has tagged about 1,200 individual mommy turtles! How cool?! Many of them come back years later (typically every 2-3 years) and are reidentified; Cotton Candy is the first turtle that the night team has encountered this season, and she was found on your beach!! She was first tagged in 2017, returned in 2021 and now again in 2025! We must be doing something right over here for her to have returned for 3 nesting seasons; let's keep up the good work of turning off our white lights after 9pm, filling in holes on the beach, and keeping our dogs on leashes.
Things are heating up at Chateaux Sur Mer!! From 2 nests two weeks ago, you are now up to 7! Woo hoo! Since we are on the subject of the turtle tagging project; allow me to introduce you to the mommas who visited your beach in the past two weeks. Lemon Creme who was first spotted in 2017 and Taco who was first spotted in 2018, are the two lovely ladies who nested on Chateaux Sur Mer's beach. Lemon Creme and Cotton Candy are from the ice cream themed year of 2017, and Taco is from the spices / seasonings theme of 2018. So far all the turtles in your section have been repeat customers, but hopefully some new space ladies will nest on your beach soon!
Have a wonderful and safe holiday weekend, and stay tuned for more updates!
Lizzy
May 9, 2025
We are back for everyone's favorite time of year! As I'm sure you are all familiar, sea turtle nesting season officially began on April 15th. We have not had much activity yet, so you'll have to settle for me talking about myself in this first update instead . I'm Lizzy, the Sea Turtle Morning Monitoring Intern for the 2025 season, and I am so excited to keep you all up to date on things sea turtle related on Sanibel and Captiva. A little about me, I am originally from the great state of New Jersey (home to the best bagels and pizza), but moved to the area about three years ago to obtain a Marine Science bachelor’s degree at Florida Gulf Coast University.
This year will be my second season with sea turtle nesting; last season I worked with FGCU and Florida Department of Environmental Protection on Don Pedro Island State park in Placida, Florida where we had 191 Loggerhead nests and 31 nests from Green sea turtles. Although it may seem like a small number compared to the 839 Loggerhead nests, 3 Green and 1 Leatherback on Sanibel and Captiva last year, we only had about 1.3 miles of beach! I was very pleased and fondly called all the hatchlings “my little peanuts”
Slowly but surely things have been picking up in the nesting world on Sanibel. Currently, we have a total of 21 nests between Sanibel and Captiva. It is very normal for these lovely ladies to have a slow start and then gradually the frequency of new nests increases until suddenly we have nests everywhere during the peak of nesting season, mid/end May to July.
Alright, now for the part you all came here for... what's going on the beach of Chateaux Sur Mer?? Currently there are two nests in this section, one on the edge of the Chateaux Sur Mer / Gulf Shores border, and one in the middle of the beach. Though the one on the border is a little close to call, it was lovingly laid by Cotton Candy, a loggerhead female that was first tagged on Sanibel in 2017 and returned to nest in 2021 and now again this year!
Typically, most sea turtle nesting programs use flat metal screens to protect the nests from predators, but for extra protection will sometimes use a cage that gets buried in the stand and creates more of a barrier between the nest and potential predators. For the 2025 nesting season, we are using the data from previous years regarding which areas have been the most affected by depredation, and focusing our caging efforts on those that had the greatest depredation rates. Unfortunately, in past years Chateaux Sur Mer has had high depredation, so all the nests in this area will be caged. But do not despair! This will hopefully reduce the nests that are predated and will allow for much greater hatchling success!! Since the beginning of nesting season tends to have a slow start, myself and Conner, our sea turtle technician, may be able to cage off nests in areas that will not be focused on as much when things start to pick up. That being said, if you see a skinny blonde girl with a staff shirt caging off nests, say hi and that you love receiving my emails and have been dying to meet me (it will make my day, even if it's not true). We will also be having some interns join us later in the season to work specifically on applying cages to these nests that are more vulnerable.
Attached are some pictures from my previous nesting season and of a cage compared to a regular screen. I'm looking forward to keeping you updated on this journey through the 2025 nesting season!
Have a wonderful weekend!
Lizzy