Blog Post By: Dalton Moore, Sea Turtle Intern
Loggerhead sea turtles are known to migrate across the world’s oceans within their lifetime. However, it has been discovered that this species does not drift the waters all on their lonesome. Loggerheads are likely referred to as “Moving Ecosystems” due to the numerous organisms that colonize the turtle’s carapace. This species may carry a diversity of abundant populations of life such as nematodes, crustacean larvae, barnacles, algae and shrimp. It is estimated that loggerheads can sustain more than 100,000 individual organisms on their approximate 35-inch shell. A recently published paper in the scientific journal Diversity shows that loggerhead sea turtles also convey an average of 34,000 individual meiofauna or organisms that are roughly between 0.032-1 millimeter in size. Jeroen Ingels, a marine ecologist at Florida State University, and his team discovered more than a hundred new species of meiofauna, primarily nematodes, that had not previously been found on the loggerheads or other turtle species. The group made their findings after examining 24 loggerheads that had migrated to St. George Island, Florida, in June 2018. The Loggerhead is considered a “keystone species,” meaning that other animals in its ecosystem depend on it for survival. Therefore, other organisms typically use their carapace to feed or migrate. It is predicted that many species will travel on carapaces to spread from ecosystem to ecosystem throughout the world’s oceans to expand. Sea turtles and their shells are also popular among fish, such as surgeonfish that like to graze those hitchhiking critters. This critical relationship becomes convenient for both the fish and the sea turtle. The fish eat algae and smaller crustaceans while the sea turtle receives a cleaning. This is important because if too many organisms live on the shell, it can affect how they streamline within the ocean.
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We had a stormy evening for Thursday's walk but we were hoping the weather would cooperate. Thankfully the storm was moving farther and farther away, so we were able to proceed with the walk portion of the program. We came across a couple nests that already had signs of emergence. There was one nest that had a couple hatchlings still at the surface and we watched as they made their way into the ocean. Another half of a mile walk down the beach and we had a nesting sea turtle ashore. She was already further along with her nesting stage, so we got to witness her lay her eggs, cover and head back into the water. The following morning we documented 7 new nests, 3 false crawls and 4 nests that emerged. It was a busier night for turtles! The nest we witnessed during our night walk program is marked as 314 on our state park beach. See below for pictures taken during the dawn patrol. We had a very short but successful walk! Just to the left of the building, there was a sea turtle ashore and she was already getting settled. Once we arrived up to view her she had just finished laying her eggs and was in the covering process. We watched her as she patted down the sand to cover and hide the eggs. Then we witnessed her crawl back and slip under the waves.
The following morning the dawn patrol team documented 5 new nests, 2 false crawls and 3 nests that emerged! The nest we saw during our program is marked as 302 on our state park beach. The dawn patrol team decided to leave the nest in situ as it is in a higher location of the beach. It may see a wash over or two with the King tide but it should not harm the nest but only benefit it, by cooling it down. Our dawn patrol team is trying to send me pictures of the night walk body pit and tracks but the island's cell phone service is preventing that at the moment. When I do receive photos I will be sure to post them here! On July 8th, we had a pleasant surprise on Edisto Beach State Park. While two interns, Dalton and Ciara, were checking a Loggerhead turtle nest, they discovered a new Diamond Backed Terrapin hatchling. This hatchling was headed towards the ocean, and it needed to be relocated to the marsh. Diamond Backed Terrapins usually lay their eggs along marshy vegetation or in the sand dunes. They lay 25-40 eggs per season between the months of April-July. By moving the terrapin to the marsh, we gave it a better chance for survival.
We have two Diamond Backed Terrapins at the Environmental Learning Center. While the subspecies of those is not known, it can be assumed that the hatchling was a Carolina Diamond Backed Terrapin. Carolina terrapins have a parallel carapace and are most similar to the Northern Diamond Backed Terrapin subspecies. For all Diamond Backed Terrapins, the females are larger than the males. They have gray skin that is covered in black dots. Other subspecies have lighter skin, but they still have the black dots and other dark colorations along their skin. After a strong thunderstorm in the afternoon, the skies cleared and we were able to continue with the walk portion of the program. After walking by the campground, we came across a nest that was possibly due to hatch. Well, this nest did not get the memo to wait and the hatchlings had already come and gone. We continued our walk to the inlet where we came across a set of tracks belonging to a false crawl. On our way back to the inlet, we were still hopeful for a sight of a sea turtle. Well thankfully, nest 10 decided to wait for our group and shortly after we arrived, the nest starting to emerge! It was an amazing sight with many hatchlings making their way to the water. It was a low tide, so they had a long trek to the sea. We stuck by the final hatchling and ensured it entered the ocean safely. The turtle vibes were high after the nest "boil" and then we were hoping to see the nesting adult. Well, not too far, down the beach and we had a sea turtle that had recently emerged. We had the opportunity to watch her lay her eggs, cover and return. She was a larger turtle, with her carapace measuring in at 44 inches. The following morning the dawn patrol team documented 6 new nests bringing our tally up to 289 nests. There were only 2 nests that emerged last night. The nest we witnessed last night is marked as 287 on our state park beach. We had a late but a great night walk on Thursday! On our way down to the inlet, we checked on nest 4 and it had already emerged! There were a lot of tracks so it looks like it was a very successful nest. We were thrilled to find that there were two hatchlings still near the surface and we got to watch as they made their long trek to the ocean and dip into the waves.
The group was hopeful to now get to see a nesting sea turtle. Well sure enough on our way back from the inlet, a sea turtle was still emerging. We waited patiently until she was at a safe stage to view. We watched as she laid her eggs, covered and then returned to the ocean. During her covering phase, we noticed she had bioluminescence on her carapace. It was neat to see it glowing as she threw sand! On our way back to the WIFI room, we passed by one other successful nest, one false crawl and another turtle that was still ashore. We quietly walked near the water's edge to not disturb her. The following morning the dawn patrol team documented 5 new nests and 2 false crawls. They also documented three new nest emergences. The nest we witnessed during our program is marked as nest 276 on our state park beach. On Tuesday's night walk we had a short walk down the beach and there was turtle tracks seen! But unfortunately she had already come and gone. It was a false crawl with a quick turnaround. Another half a mile walk down the beach and there was a turtle ashore already laying eggs! There were other members of the public already viewing her but they did the right thing by keeping their distance to ensure she nested successfully. We were able to get a closer look and answer more great turtle questions while she finished up laying, covering and then returned to the ocean. It was a beautiful night under a starry sky with a great breeze to keep the noseeums at bay.
The following morning the dawn patrol team found 7 new nests and 6 false crawls. The nest we saw during our program is marked as 262 on the state park beach. It was determined to be in a safe location that was not in need of relocation. Once I receive photos from the dawn patrol team, I will be sure to share more of the morning turtle activities documented! Blog Post By: Sarah Glover, Sea Turtle Intern
If you’ve been on our beach in the morning, you’ve probably seen our turtle team out patrolling the beach and marking nests. But how do we identify nests and find the eggs? Well, there are a few things we look at. The first thing we observe are the tracks left by the turtle. We look for “v” shapes in the sand to figure out which track was her incoming and which was her outgoing. The “v” points in the direction in which the turtle came. For example, if it points to the ocean, then that is the path she took out of the water. Identifying her incoming and outgoing tracks allows us to determine which way the turtle was facing while she was laying her eggs. Looking at the tracks also helps us to determine which species of sea turtle the crawl belongs to. Loggerhead sea turtles, the primary nesters on our beach, move with alternating limb movements, which means they move one flipper at a time. Other species, such as the green sea turtles, move with parallel limb movements, moving both flippers at the same time and pulling themselves up. The next thing we look for in our “turtle scene investigation” is thrown sand. Once the turtle has made her was up the beach and found a good spot, she begins to make a body pit by throwing sand with her front flippers. She may even tear up vegetation in this area. She then uses her back flippers to scoop sand and dig an 18–24-inch egg chamber. When she is finished laying her eggs, she will spend a lot of time covering them up. She throws lots of sand and pats it down with her full body weight to ensure they are well hidden. In other words, a lot of sand is thrown and moved around during the nesting process. If we see tracks leading to a body pit with thrown sand, there is a good chance that eggs are hidden below. However, if there is no body pit or if not much sand has been thrown, then the turtle may not have nested. This is what we call a false crawl. Finally, once we have identified that we are looking at a nest, we use a device called a probe to find exactly where the eggs are buried. There is an air pocket above the eggs in the chamber that we feel for. We push the probe into the sand and when we feel a slight drop, we know the eggs are buried below. The turtles had us getting our steps in during our program! We walked all the way to the inlet without a sighting. Near the inlet a turtle starting emerging near the tail end of our group, but decided not to come ashore. We were hopeful she was going to find another spot! On our walk back, we had a turtle ashore! We took a look through the night vision monocular to see her as she was still trying to find a spot to nest. From a distance I could faintly see a throw of sand and hear her shuffling about. Unfortunately, she did not settle on a location and turned around and headed back to the ocean. We got to see her closer as she made her crawl into the waves. When we got back to the office building, I continued the walk to the southern section of our beach in the hopes we may have had a turtle ashore. There was a fresh nest with no turtle in sight! She must have come up on our walk to the inlet and already finished laying her eggs and returned. The following morning we documented two new nests and two false crawls. With such few activities last night, I am so happy we at least got to see a sea turtle! The nest near the Pavilion was relocated as it was below the Spring high tide line. It is marked as nest 256. It had a total of 121 eggs and is now in a more suitable location. The other nest found had a very long crawl so she would have nested early this morning. That nest is marked as 257. See below for pictures taken from the morning patrol. Blog Post By: Christine Segnari, Sea Turtle Intern
On Edisto Beach State Park, Loggerhead Sea Turtles face several predators including ghost crabs, racoons, laughing gulls, and, occasionally, other loggerhead turtles. (“Other loggerhead turtles” is referring to when turtles lay their eggs on top of another nest and crush the eggs of their own nest or the other nest when trying to cover their eggs). However, on other beaches and in the wild, these turtles have tiger sharks, coyotes, and humans as their predators. Humans contribute to turtle’s endangerment through discarding fishing lines and plastic. More commonly, in necropsies plastic is found in turtles’ stomachs. Additionally, boat strikes are common to Loggerhead Sea Turtles causing them to be injured or possibly die. Last week on Dawn Patrol, we followed a stressed turtle’s tracks up into the vegetation. Her tracks came up into the vegetation, did a loop around, came back down and went back into the vegetation, did another loop around, and then her tracks returned into the ocean. Back by one of the vegetation spots, there was an abandoned egg chamber surrounded by raccoon prints. Additionally, there were raccoon prints all over her tracks, meaning she was most likely bothered by raccoons while trying to lay her eggs. Though this is the first time I have seen something like this, raccoons are most one of our devastating predators on Edisto Beach State Park. They can get into nests quickly and eat a large amount of the eggs inside one nest. This summer, one nest lost 99 eggs overnight due to raccoons. We had the shortest walk of the season on Thursday! As soon as I stepped out on the beach, I saw a turtle ashore in front of the office building. Unfortunately, there were members of the public taking flash photos of this turtle. Thankfully she was in the egg laying stage and was not too disturbed by this activity. Regardless of the stage she is in, if on the beach by yourself, you need to give her 20-30 feet and no flash photography is allowed. The following morning we documented this nest first, making it nest 242 on our beach! It was too low to the tide line, so we carefully relocated it. We counted 144 eggs! It was a busy morning patrol. In total we documented 12 new nests and 13 false crawls. See below for pictures taken of nest 242 and the relocation. Our night walk on Tuesday was another short walk. We had a sea turtle emerging to the right of the office building as soon as we stepped out onto the beach. We waited as she found herself a suitable spot. She crawled up towards the dunes to an area that is well above the Spring high tide line - so no relocation necessary!
The following morning the dawn patrol team documented 9 nests and 2 false crawls! The nest we saw on our night walk program is marked as 230 on our beach. The dawn patrol team dealt with storms during their patrol but they did get the reward of rainbows! On Saturday night we had the shortest walk so far this season! After the presentation concluded, I went out to check to the right/south end of our beach, which is not as popular of a nesting spot, when I came across turtle tracks! It was a very dark night so it was difficult to see her but I could still hear that she was digging. The group was able to witness this sea turtle a bit closer once she was at a safe stage to do so. The next morning we had a busy patrol! There were 9 nests and 6 false crawls documented. The nest from the night walk was the first nest found in the morning, so now it is nest 206 on our beach! See below for a few pictures of the night walk nest! On June 23rd our dawn patrol team found 6 new nests! The last nest they marked is nest 200 on the state park beach! The turtles are having another record or near-record year and we look forward to seeing how many more we will find as the season goes on. Our nesting numbers have been similar to the record year in 2019 when we ended up with 351 nests. How many nests do you think we will have by the time the season wraps up? Stay tuned to find out!
Blog Post By: Sarah Glover, Sea Turtle Intern During dawn patrol on June 8th, we found a loggerhead nest that needed to be relocated. This turtle could not quite make it up the steep scarp, so we decided to move her to a safer location down the beach. As we were removing the eggs from the original chamber, we discovered something rare. Several eggs in this clutch were not the typical ping-pong ball shape of most loggerhead sea turtle eggs. Instead, they were more oblong and contained multiple yolks. Some looked like one big, oval egg, while others looked like several eggs fused together. There were also several broken eggs within the nest, one of which was used as our sample for the DNA study we are a part of. Believe it or not, the misshaped eggs found in this nest may still be viable. In multi-yolk eggs, the closer the yolks are together, the more likely it is that the egg will hatch. However, since we do not know how constricted the yolks are, we will not know whether or not these eggs were viable until we conduct an inventory on the nest. Inventories take place after a nest has hatched, which is 45-60 days after the eggs are laid. We will post an update on these eggs after the inventory, so stay tuned! We did not have to walk far on Saturday and we already had a turtle ashore. She recently crawled ashore when we arrived and was still completing her body pit and egg chamber. We waited patiently until she was at a good stage to view her. It is hard to tell at night but it appeared like this nest was in need of a relocation. Well, the following morning the team did determine her nest was too low and below the Spring high tide line. They carefully moved her 98 eggs to a higher and safer location. The sea turtle nest we witnessed is now marked as nest 175 on our beach! There was a total of 9 nests and 6 false crawls documented on Sunday morning See below for pictures taken during dawn patrol of nest 175. Blog Post By: Dalton Moore, Sea Turtle Intern
After hatchlings leave the nest, some turtles slowly reach their way to the Atlantic Ocean. But what happens after these courageous swimmers paddle themselves into the moonlight? This time is a bit of a blur that scientist have termed the “lost years” of a sea turtles’ life. Furthermore, there is no concrete evidence about where hatchlings exactly travel. Marine biologist from the University of Central Florida Kate Mansfield stated, “We don’t know where the turtles go, how they get there, how they interact with their environment.” For the Caretta caretta species (Loggerheads), the lost years phase lasts from 7-12 years from birth. This is considered a huge portion of their life that conservationist do not completely understand. Groups along with Kate Mansfield’s team have found ways to determine where the hatchlings advance. By tagging and tracking via satellite, adolescent turtles spend their early years navigating long distances and loitering around seaweed beds within the Sargasso Sea. In order to conserve energy, it is expected that neonatal loggerheads take the Gulf Stream and follow the current into the mid-Atlantic where the genus Sargassum floats upon the surface. Within this area the infant turtles spend their time feeding on small crustaceans, hydrozoans, sargassum seaweed, jellyfish, etc. The turtles will also use the seaweed to stay hidden from predators. If they did not avoid coastal areas on the continental shelf, predators such as seabirds and sharks would likely interrogate them. They will continue to feed here until they become the approximate size of a dinner plate and travel back to their general area of birth where predators will not be as much as an issue. Our Night Walk on Thursday was cut short due to a storm that moved in. As soon as we finished the presentation, the rain came down and the lightning alerts showed it was too close. The following morning there were 7 nests and 6 false crawls documented. See below for some of the pictures taken during patrol. Nests 163, 164, 165, 166, 167, 168 and 169 were all marked and protected. It was a full moon night walk and the group was feeling optimistic about a turtle sighting! It was a very hot night with very little breeze and the high tide was just receding. Only 0.2 of a mile walk down the beach and we had a sea turtle ashore! We waited patiently as she found her spot and began to dig. When she was at a safer stage, we watched as she finished laying her eggs and covering them back up. She was a larger loggerhead measuring in at 108cm (~42inches) in carapace length. We watched as she made her crawl back to the ocean under the full moon light. The following morning there were 5 new nests found and 4 false crawls. The turtle we saw on our walk is marked as nest 147 on our beach. See below for pictures taken from patrol! Blog Post By: Christine Segnari On the first night walk of nesting season, the EBSP Staff Night Walk on June 2nd, we had an exciting discovery. We found a PIT tag in this turtle’s shoulder, and this is the first time we have encountered a sea turtle with a PIT tag during a night walk. PIT tags, also known as Passive Integrated Transponders, are used by both aquariums and several beaches to track the sea turtles they encounter or help. While Edisto Beach State Park (EBSP) do not tag the Loggerhead Sea Turtles that appear on our beach, we do check for these tags with any turtle we encounter. Using a scanner, we are able to detect the microchip (the PIT tag), and we get a series of numbers identifying the sea turtle. By scanning the PIT tag of our night walk turtle, we were able to see its long journey. Notably, back in 2016, this sea turtle had nested at Wassaw Beach in Georgia (where they do tag the sea turtles they encounter). It was amazing to see the nesting history of this turtle and get a more accurate understanding of where turtles nest. Though it was once believed that Loggerhead Sea Turtles return to the exact same beach they hatched from, that is not entirely true. Sea turtles use the Earth’s magnetic field as a guide to find the beach to nest on, meaning the turtle may not be completely accurate and nest on a different beach throughout each nesting season. However, some turtles are able to return to the beach they hatched from. Through our DNA samples, we were able to see that one sea turtle laid all four of her nests on Edisto Beach State Park one season, all within our 1.5 miles of beach. We had a turtle-filled night walk on Saturday. We had a very small night walk group of only 5 participants, as the storms earlier in the afternoon must have caused hesitation to sign-up. Thankfully all of the storms had moved on and we had a beautiful night for a walk. As soon as we got on the beach, we had a turtle start to make her crawl out of the surf. Unfortunately, individuals walking from the other direction did not know what it was and when they approached closely, she turned around and left. We continued on down the beach and found a set of tracks almost a mile down the beach. This time the turtle was well above the tide and back in the dune grass. At the same time we had another turtle way down the way start emerging. We were hopeful that one of these turtles would successful lay a nest! Unfortunately the one we were at crawled all the way back to the primary dunes and seemed to be fed up with all of the vegetation. We witnessed her as she crawled back into the ocean. In the morning, I did confirm that this was a false crawl. The second turtle also decided to turn around. So although we had turtle activity we had not yet seen one lay a nest. On our way back from the inlet we finally got the chance to witness a nesting sea turtle! She was way up in the dunes at the campground. We are grateful for the beach goers that witnessed her that they kept their distance and kept their movement to a minimum so she would not be disturbed. We saw her just as she finished laying her eggs and then watched as she covered them back up, keeping them protected down below. In the morning we found 8 new nests and 3 false crawls (not including the ones we saw already washed away by the tide). The turtle we saw successfully nest is marked as nest 135 on our beach! See below for pictures taken from the dawn patrol! The turtles made us work for it on our night walk last night as all of the activity was at the inlet, 1.5 miles down the beach. We had a turtle emerging, so we waited patiently as she made the long trek at low tide up the beach to find a suitable spot to start to dig her egg chamber. While we were patiently waiting for this turtle to start to lay, another turtle started to emerge from the ocean! Through the night vision monocular, the group got a close up look as this other loggerhead sea turtle crawled up to the dunes to create a nest. We waited for the second turtle to get up high enough in the dunes and then quietly passed below near the ocean to go see the first sea turtle. We got to witness this sea turtle cover her eggs and return to the ocean! The turtle we saw nest during the night walk program is now nest 125 on our beach! In the morning the dawn patrol team found 3 new nests and 1 false crawl. The other turtle that we witnessed during the walk also was able to successfully nest, which is marked as nest 124. Nest 125 was in need of a relocation, so the team carefully relocated her 113 eggs to a chamber in a higher and more suitable location. Check out the photos below taken during the dawn patrol! Blog Post By: Sarah Glover, Sea Turtle Intern
Loggerhead sea turtles are the primary species that nests here at Edisto Beach State Park. Since their nesting season begins in May and continues throughout the summer, the temperature can change quite a bit while the eggs are incubating. As the season moves along, the air and sand temperature increase. However, it can also fluctuate depending on the weather. Interestingly enough, the temperature of the sand actually affects the sex of the hatchlings. If the sand is 85°F or higher, the eggs are more likely to be female, while sand that is less than 85°F tends to produce more male turtles. In other words, “hot chicks, cool dudes.” Eggs that are laid early in the season tend to experience cooler temperatures and, therefore, are likely to produce more males. This is also true of nests that experience more wash overs. This year, sand temperature loggers have been installed all along the state park beach for the first time. Some are up in the dunes, while others are farther down near the spring high tide line. These loggers will provide us with information about the temperature of the sand – how it changes throughout the nesting season and how it differs between the higher and lower areas. This information will allow us to see how location and fluctuations in the sand temperature affect the nests that are located in the areas around them. Our Night Walk program has started once again and we are excited to have started off with a successful walk! After the presentation wrapped up, we began our walk under a brightly lit beach under a clear starry sky. Only 0.2 of a walk down the beach and there were fresh turtle tracks leading up towards the dunes. A group of campers were waiting patiently in the dark and from a 20ft distance in order to ensure she can nest without disturbance. We appreciate them for following these rules to keep our sea turtles nesting safely!
When we arrived to her tracks she was still digging the egg chamber. We waited patiently until she started to lay her eggs. As we are permitted to conduct these walks, we were able to get a closer view of her dropping the eggs, covering and then watched as she swam down beneath the waves. In the morning, our intern, Sarah, and past intern and now volunteer, Chase, documented this nest as 116 on our beach. There were a total of 4 new nests and 2 false crawls. They decided this nest was situated high enough on the beach so no relocation was necessary. If you would like to adopt this nest, be sure to visit the Camp Exchange or the Environmental Learning Center and ask to adopt nest 116! This was the perfect walk to kick-off the start to our Night Walk program. If you would like to sign up for a night walk, click on the button below: Blog Post By: Dalton Moore, Sea Turtle Intern Occasionally, sea turtle nests are in need of relocation. A relocation occurs when a female sea turtle lays her eggs below the tidal line. If these eggs are not relocated, it may result in damaged eggs that experience severe washover. Another reason for relocation could also be due to high traffic areas on the beach. Lastly, If people walk on undocumented nests, this could cause severe damage to the clutch of eggs. To avoid any of the situations that we just discussed, our staff has been permitted by the Department of Natural Resources in South Carolina to document and relocate nests if necessary. We establish where the egg chamber is within a nest and communicate with one another to determine if it is needed to be relocated. If this is the case, we will then place soft sand in our relocation bucket to allow a smooth bottom for the eggs. We then removed them from the egg chamber to the bucket. The eggs will then be moved without any rotation to ensure the developmental stage is not stunted whatsoever. The process is very tedious, but it is mandatory to have a successful hatch rate. Approximately 120 eggs will be removed and placed into the relocation bucket. After the eggs are dislodged from the chamber, we place a soft towel and sand on top of the bucket to help cover the clutch. It is essential to avoid any significant amounts of sunlight directly on the eggs; this could damage their development. We then create an artificial egg chamber that is highly similar to the original nesting chamber. Ordinarily, the egg chamber will be 18-24 inches in length and 6 inches in diameter at the top. The diameter gradually increases to 12 inches as the cavity gets deeper and forms an hourglass shape. We then will put the eggs into the artificial chamber, making sure to be cautious and not rotate them whatsoever. Finally, we then will cover the eggs with soft sand and mark where the artificial hole. As you would with an in-situ nest, we screen the relocated area and put all required stakes around it. We have data recorded from previous years that show how successfully relocated nests are compared to in-situ nests. For example, Edisto Beach State Park had a relocated percentage of 31% in 2021. The success rate of the relocated nest was similar to the in-situ nests, with a mean success rate of 81.6%. As of now, we have 81 nests where 39.5% have been relocated. We are optimistic with the proper training we have, and with the permission of the Department of Natural Resources, our success rates will be proven to be thriving! |
Leah SchwartzentruberSea Turtle Biologist Archives
September 2023
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