See, Turtles! Erika Willits



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See, Turtles!
Erika Willits
April 7, 2016

Sea Turtles are a species of marine reptiles. In “Marine Reptiles”, an article study, it state that there are 12,000 species and subspecies of reptile, but only 100 of them have reentered the ocean. There are seven species of Sea Turtles, unless of course if you count the Chelonia Mydas Agassizi then there would be eight. About 260 million years ago reptiles evolved from aquatic amphibians. Only 150-200 million years ago modern reptiles started to appear. From those reptiles arose the marine reptiles including Sea Turtles, along with Sea Snakes and as well as few others.

The same article tells us that Sea Turtle came from terrestrial or freshwater turtles. Sea Turtles arose 100 million years ago. They are can be found throughout tropical, temperate, and subarctic waters. Some are known for long journeys across oceans. They usually nest along Central or South American Coasts and the Caribbean islands and are sometimes seen as far as Scandinavia.

The migration of Sea Turtles is a big aspect of their lives. In “Climate influences the global distribution of sea turtle nesting” it states that Sea Turtles travel hundreds or thousands of kilometers of ocean and most of the time they do this alone. However, in “Marine Reptiles” it state the only exception to this is during nesting season. It’s during this time they may travel to their home beaches in groups. Even then they still swim about 700 meters between each individual. This is nothing like what we see in Disney’s Finding Nemo. How do the turtles even know where they’re going? The answer is they have geomagnetic sensing, this allows them to find the same geographic region they usually nest on. Some adult females have the tendency to nest on the same geographic region as the beach they hatched from. Regardless, there’s not a precise way of knowing for sure if they make it to the same beach.

As previously stated most Sea Turtles are endangered of becoming extinct, all except Olive Ridley and Flatback Turtles. Loggerhead Turtles (Caretta Caretta) are endangered. Green Turtles (Chelonia Mydas) are endangered. Leatherback Turtles (Dermochelys Corlacea) are critically endangered. Hawksbill Turtles (Eretmochelys Imbricata) are critically endangered. Atlantic Ridley Turtles (Lepidochelys Kempii) are critically endangered. The biggest reason for this is overexploitation or destruction of nesting areas. Tourists and/or locals are the cause both these of these problems. We find out in the article that specifically marine fishers overexploit eggs and adult females in the nesting beaches and juveniles and adults in foraging areas as well as degrading marine and nesting habitats. “Analyses of subpopulation changes at 32 Index Sites distributed globally show a 48% to 67% decline in the number of mature females nesting annually over the last 3 generations.”

In another article “Size Scaling in Western North Atlantic Loggerhead Turtles Permits Extrapolation between Regions, but Not Life Stages” it very clearly states the obvious from the title. Scaling is a way of measuring or testing something. The reason people scale Sea Turtles is because it will help with the conservation of these animals because they can better understand the biology of them. Scaling isn’t very efficient on telling what stage of life species of turtles are in, however it’s great for telling what region a turtle is from. This is because, for example, Loggerhead Turtles neritic juveniles and adults are easily put into the same group.

In the article “Assessing the relative importance of conservation measures applied on sea turtles…” it talks about the fact that there’s been an increase in nesting where there were conservation activities on beaches that are nesting sites. It also stated that there is a potential for an increase in hatchling production, which would help the population of Sea Turtles. In other words, the efforts to save and preserve Sea Turtle nest is well on its way.

As we all know Sea Turtles spend a great deal of their time in the ocean, However, they do have to lay their eggs on a terrestrial environment. They accomplish this by burying them in the sand in effort to protect them and leaving them for months until they hatch. They then have to find their way to the ocean on their own. However, there is a problem because over time the amount of adequate places for Sea Turtle nesting has decreased by a significant amount. There are lots of variables that distinguish whether or not a beach is acceptable for nesting. In the article “Climate influences the global distribution of sea turtle nesting” David A. Pike tries to figure whether or not climate limits current sea turtle nesting. He also wants to know if this could potentially shapes these animals population.

In the article Pike tells us that Sea Turtle eggs are flexible and are vulnerable. Their eggs are sensitive to various different variables of their environment, both hydric and thermal conditions. Adult female Sea Turtles pay close attention to the where they lay their eggs because amount the moisture and temperature could potentially kill the embryos. Another important quality of these nesting areas is that they have to be available and consistently high quality for months at a time. Without access to sandy beaches reproduction would be impossible.

Pike tells us that a majority of nesting is in tropical or subtropical regions. He states the importance of the conservation of these regions is that adult females have a natural tendency to return to the same geographical location that they were hatched from. However, Sea Turtles will migrate to different areas that have better suitable temperature and precipitation for their eggs. Adult females will make specific precautions to make sure the eggs have a fighting chance such as burying them in an open area instead of under a tree where the shade from the tree might decrease the temperature. There is also a variation in depth in the sand to each species because the size of the species determines whether or not they can handle colder temperatures that are deeper within the sand, keeping in mind if the hole isn’t deep enough there is a potential threat of hungry predators.

TSD stands for temperature-dependent sex determination. In the article entitled “Marine Reptiles” we learn that there are species of Sea Turtles that are TSD such as Loggerhead, Green, Leatherback, and Olive Ridley Turtles. The problem with this is that over time global warming can affect the sex ratios in these species of Sea Turtles. Warm temperature while a Sea Turtle is being produced creates a female. With an increase in female production there will be a shortage in male production and this will complicate the amount of baby sea turtles that are made. The reproduction of these species of Sea Turtle would decrease and eventually lead to their extinction. Though this would only happen over the course of many years, this fear could potentially kill off many species of Sea Turtle.

Sea Turtles are incredible animals and have been around for millions of years. Climate change does indeed affect these animals in a huge way. Not only does it affect the success of the reproduction but it could also take a toll on the sex ratios and eventually the population. These negative effects both unfortunately threaten the very existence of these animals.



Works Cited
Arne Redsted, R., Murphy, J. C., Ompi, M., Gibbons, J. W., & Uetz, P. (2011). Marine Reptiles. Plos ONE, 6(11), 1-4. doi:10.1371/journal.pone.0027373
Marn, N., Klanjscek, T., Stokes, L., & Jusup, M. (2015). Size Scaling in Western North Atlantic Loggerhead Turtles Permits Extapolation between Regions, but Not Life Stages. Plos ONE, 10(12), 1-23. doi:10.1372/journal.pone.0143747
Mazaris, A. D., Kramer-Schadt, S., Tzanopoulos, J., Johst, K., Matsinos, G., & Pantis, J. D. (2009). Assessing the relative importance of conservation measures applied on sea turtles: comparison of measure focusing on nesting success and hatching recruitment success. Amphibia-Reptilia,30(2), 221-231. doi:10.1163/156853809788201180
Pike, D. A. (2013). Climate influences the global distributuion of sea turtle nesting. Global Ecology & Biogeography, 22(5), 555-566. Doi:10.1111/geb.12025
Santidrián Tomillo, P., Genovart, M., Paladino, F. V., Spotila, J. R., & Oro, D. (2015). Climate change overruns resilience conferred by temperature-dependent sex determination in sea turtles and threatens their survival. Global Change Biology, 21(8), 2980-2988. doi:10.1111/gcb.12918

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