Sand dunes 50 feet tall. A river of sea oats flowing in the wind. Mounds of sand with baby marine turtles developing underneath. This is what my summer looked like while on a mission to find out how loggerhead marine turtle hatchlings are influenced by local climate and their nest environment. My project took place at St. George Island State Park and St. Joseph Peninsula State Park, both of which are on the coast of the Florida Panhandle. Although they are only an hour a part, these beaches have quite a few differences. Compared to St. Joseph, St. George Island State Park has darker sand, less erosion, and fewer loggerhead marine turtle nests. These differences have already affected the marine turtles and the season isn’t over! So far, the incubation period at St. George has been shorter by about a week and more nests have washed away by storms (big and small) at St. Joseph due to how dynamic the beach is.
How did I accomplish my field work? St. George has an existing weather station, but St. Joseph did not. Therefore, I deployed one to monitor the air temperature, rainfall, humidity, wind speed and direction, and soil moisture. These weather stations allowed me to record the local climate. To gather information on the nest environment, I recorded how close the nest was to the high tide and vegetation, I collected a sand sample to measure thermal properties of the surface sand for each nest, and I deployed a temperature logger about the size and shape of a watch battery. Each morning, I would identify a loggerhead marine turtle nest, locate the clutch of eggs, carefully remove half of the eggs, deploy my temperature logger, and gently put the eggs and sand back how I found it. I managed to deploy temperature loggers into 31% of nests at St. Joseph and 21% of nests at St. George. This brings me to a total of 51 nests! Before classes started back up, I managed to complete an inventory of some of these nests at both locations. An inventory is when you open a nest after hatchlings have emerged to count how many eggs hatched (hatching success) and how many babies that hatched made it out of the nest (emergence rate). These are exciting because sometimes you see a hatchling still alive that struggled to make it out with its siblings or there are some unhatched eggs that have various stages of the embryo inside that stopped developing. I’m looking forward to returning to both parks periodically to continue gathering this information as well as my temperature loggers and weather data.
This work could not have been done without the help of the Sea Turtle Grants Program and the always helpful staff at both state parks. The Sea Turtle Grants Program (www.helpingseaturtles.org) is funded by the money used by individuals to purchase marine turtle license plates in Florida. Receiving this grant allowed me to purchase the weather station I deployed in St. Joseph, the GPS I used to record the location of my nests, and the temperature loggers I placed within the nests.