Although we did not see a nesting sea turtle on our night walk, we did get to witness a couple turtles make their trek back to the ocean. These turtles did not successfully nest but crawled ashore and decided it was not the spot for them. The one particular turtle was unable to crawl up the steep scarp that had formed due to erosion. On our trek back to the WIFI room, there was another turtle ashore. It almost appeared to be parallel tracks. With our permit, we are only able to witness loggerhead sea turtles as other species nesting on our beach are rare. We quietly passed on by, in the morning we confirmed that turtle crawl to also be false. We documented 4 new nests and 10 false crawls in the morning. See below for pictures taken during the dawn patrol.
0 Comments
Blog Post By: Lilli Stanley, Sea Turtle Intern
One of my favorite shells to collect from the beach are the beautiful whelk shells. They have a spiral pattern and often have stripes and “knobs” or spikes sticking out of them. They look similar to conchs which they are often mistaken for. However, whelks are not just a shell. They are a protective outer covering made by the whelk snail that lives inside of them. The spiral design of these shells are formed when the snail uses its mantle to produce calcium carbonate to extend their shells around a central axis, producing “whorls” or turns. Loggerhead sea turtles love Whelks as well, but they are less interested in the shell than what is inside. Loggerheads use the strength of their massive jaws to crush the whelk shell so that they can eat the snail inside. Their strong jaws are what gives loggerheads their name. They must have a large head to be able to exert more than 500 pounds of force through their crushing jaws. Besides whelks, Loggerheads also love to eat jellyfish, mollusks, horseshoe crabs, and other species of crabs. Since being at Edisto, I have become even more interested in whelks and got to spot a live one moving along the waters edge at Botany Bay last night. Even though the broken whelk shells may not be as pretty for collecting, I like to imagine that a Loggerhead got to it first and broke it apart for a sea turtle snack. Starting out our night walk, there was a lot of human activity on the beach. Unfortunately many white lights were being used but after speaking with the beach goers, they turned them off as they just did not know. We were approached by other members of the public that said a turtle was laying eggs just down the way. When I made it closer to the turtle, I noticed she was still chambering, digging down to create the chamber prior to laying eggs. We patiently waited as she finished digging and began to lay. We witnessed her lay the eggs, cover them back up and then return to the ocean. The following morning, we had to relocate those eggs as she nested well below the Spring high tide line. There were a total of 107 eggs in the nest. They are now in a safe location and marked as nest 146! There were only two nests documented and six false crawls. The two nests were right near each other, so I guess it was an ideal spot! See below for pictures taken from the dawn patrol. We had a tougher walk on Thursday with higher tides and soft sand, however, it was all worth it when about 3/4 of a mile down the beach, we had a turtle ashore! I confirmed that the turtle was just finishing up laying her eggs. By the time the group arrived, the turtle was covering with her hind flippers, shortly after she started to cover with her front flippers. We watched as she covered and made the turn to head back into the surf. As it was high tide, she did not have far to crawl. Her nest was situated below the Spring high tide line, so the following morning, the dawn patrol team moved it to a more suitable location. The nest we saw on the night walk is nest 137 on the state park beach. The following morning we also had a nesting sea turtle that was just heading back into the ocean at 6:30am. We got to watch her enter the surf and take a photo as it was daylight. See below for photos taken during the dawn patrol. There were three new nests and three false crawls documented. We had a fun night walk on the Tuesday night as we hosted the Tour De Turtles group! Tour De Turtles is a group that goes to the 4 different coastal parks to experience a different sea turtle educational program. At Edisto Beach State Park, the group goes on a night walk and the following morning can go out for a guided morning walk. On our night walk, we had a turtle ashore as soon as I went out onto the beach. She was just emerging from the surf line. Unfortunately, she went up to the dunes and must not have liked the vegetation as she turned around and headed back to the ocean. We got to witness her as she made her way back to the water. A little further down, there was another turtle coming ashore and possibly the same one! This turtle went up to the dune vegetation again and started to dig, however, with the heavy presence of roots, she ended up abandoning the egg chamber and decided to try elsewhere. Again, we were able to witness this sea turtle heading back to the ocean. Nearby lightning had us end the walk but with two turtle sightings, we were all thrilled! The following morning on the guided morning walk, the group was able to witness nest 127 get moved from a very low location to a more suitable spot above the Spring high tide line. See below for photos taken during the dawn patrol. Blog Post By: Elaine Walters, Sea Turtle Intern
Loggerhead sea turtles spend much of their juvenile life in an area of the Northern Atlantic known as the Sargasso sea. The hatchlings emerge from their egg chamber en masse after nightfall (generally queued by a drop in sand temperature). After this emergence, which is also known as a boil, the hatchlings swim for approximately three days to reach the Sargasso sea. Here they spend much of their time until they reach sexual maturity at about thirty years old. This period of sea turtle development is sometimes called the lost years, as little is known about their exact behaviors. The Sargasso sea is formed by the circulation of the ocean. It is bordered not by landmasses, but rather by strong currents of water. These currents are formed by the Earth’s rotation and by the differential heating of the Earth by the sun. As the earth rotates, the water in the ocean wants to follow. If there were no landmasses, the water would spin around the globe unimpeded; however, when the water hits the land, it must turn. This creates spirals of water with four boundary currents. There are many other areas of the ocean that experience these as well, and they are referred to as gyres. These gyres often collect things within their boundaries, including plastic as more human waste makes its way into the ocean. In the case of the Sargasso sea, it has become the home of great mats of brownish seaweed called Sargassum. In addition to sea turtles, these mats provide shelter and food to many organisms (some of which become food for young turtles). This is significant because the open ocean is often limited in structure and food resources, both of which are provided by sargassum. Because of global climate change, the circulation that causes this gyre and subsequent open ocean ecosystem to form and thrive may be threatened. More data is still needed to determine the exact ramifications of these changes; however, it has been shown that these currents are shifting and changing due to higher temperatures (Yang et. al., 2020). The effect this may have on the life cycle of loggerhead sea turtles is still unknown, but it is possible that it could pose challenges in the early stages if they have to travel longer distances to reach relative safety and food sources. Yang, H., Lohmann, G., Krebs-Kanzow, U., Ionita, M., Shi, X., Sidorenko, D., et al. (2020). Poleward shift of the major ocean gyres detected in a warming climate. Geophysical Research Letters, 47, e2019GL085868. https://doi.org/10.1029/2019GL085868 We had a successful night walk on Saturday with a view of a turtle laying eggs, covering and returning to the ocean. This turtle also had bioluminescence on her carapace, causing her shell to glow when she would throw sand backwards. While measuring her carapace and checking for a PIT tag she was making some noises at us, clearly she was a turtle that meant business! We wait until she is late stage covering to measure and check for tags in case it would disturb the turtle. She finished up covering then made a turn for the ocean. While she was nesting, the group got to use the night vision monoculars to get a view of her head, as we only keep the red light to the back of her and away from her field of view. The following morning we documented this nest as 119 on the state park beach! There were 5 nests total that were documented during turtle patrol. See below for a few pictures taken during the morning turtle adventures. We only had to walk half a mile and we got word from campers that there was a turtle ashore! We thanked them for keeping their distance and respecting the turtle to ensure she could nest without disturbance. By the time we guided participants to the turtle, she had just finished laying eggs and was in the process of covering them. We watched as she moved and patted the sand to keep them protected. The turtle's carapace had a heavy presence of bioluminescence, which caused her shell to glow when she really started to throw sand. It was an amazing sight to see! On the way back to the WIFI room after witnessing the turtle enter the ocean, we passed by one track, where a turtle was still ashore and another set where a turtle had already come and gone. The following morning, our dawn patrol team recorded 5 new nests and 3 false crawls. The nest seen on the night walk is marked as 104 on the beach. The dawn patrol team also witnessed a sea turtle still ashore and heading back to the water at 6:30am! See below for photos taken of some of the other turtle activity seen in the morning. We walked to the inlet and back without a turtle sighting. We did see a short false crawl and were hopeful that turtle may appear again. After concluding the walk we did a final check past the white office building towards the Pavilion and spotted a turtle ashore! With the use of the night vision monocular, we noticed the turtle was still digging an egg chamber. We did not have to wait long and the turtle had started to lay eggs! We watched as she laid her eggs, covered and returned to the ocean. It was a long crawl as it was still low tide. The next morning we documented this nest as 98 on our beach! We relocated the 133 eggs to a new location as the original nest was situated below the Spring high tide line. It is now protected with a new metal cage to deter raccoons from digging into the nest. We documented three new nests this morning and two false crawls including one during our dawn patrol, as a turtle started to emerge from the ocean but turned around shortly after. See photos below taken during the dawn patrol! We held our first night walk of the season on June 6th! As we were going through the presentation on the loggerhead sea turtle, we listened to heavy rain outside and saw flashes of lightning. We were still staying hopeful that it was a fast moving storm. Sure enough, we only had to wait another 15 minutes after the presentation wrapped up until it was safe enough to walk on the beach. We went for the 1.5 mile walk to the inlet with no turtles seen. It was a tough walk with the high tide and natural beach debris. We did get to see a starry sky, a couple of shooting stars and some bioluminescence but sadly, no turtles were spotted. The following morning on patrol we only found one nest. This nest had a very long crawl, so this turtle must have come ashore during the early hours of the morning. This nest is now documented as nest 75 on our beach! See below for pictures taken from the morning patrol! |
Leah SchwartzentruberSea Turtle Biologist Archives
September 2023
|