How Can Hurricanes Impact Sea Turtles?

How Can Hurricanes Impact Sea Turtles?

When looking into some potential ideas for my research project, I found that the unique barrier islands and amenities of Cape Lookout National Seashore (CALO) provided for some really cool projects!

Ultimately, I knew I wanted my project to incorporate sea turtle disorientations events. When sea turtles are on the beach, whether it be a nesting mother or hatchling, external factors may impact their navigation and lead them to disorient. For example, hatchlings emerging from their nest use the brightest source at nighttime, the moon reflecting over the ocean, as the primary light source to navigate towards the water and begin their lives. However, issues like light pollution or other human disturbance can cause turtles to disorient (meaning they continue in a constant direction away from the water). A sea turtle disorientation event is defined when hatchlings within the observed nest disorient.

When sea turtle hatchling emerge from their nest, they crawl towards the beach following the moonlight. You can visualize from this hatch out that the turtles did not disorient, as all of their tracks are heading seaward (Image Credit: SeaTurtle.org)

On the contrary, this is an example of sea turtle hatchlings that were disoriented. You can see the tracks traverse different areas of the sand without any intended direction. (Image Credit: ABC News)

 Originally, I was interested in seeing how Off Road Vehicle (ORV) use on the beach could impact sea turtle disorientations. CALO allows ORV’s to traverse the beach during sea turtle season. I was curious to note how nighttime activities like creating bonfires or vehicles headlights at nighttime might play a role in hatchlings disorienting. Unfortunately, most turtles will begin hatching once my internship is over, so this project was not entirely feasible.

Instead, I am recentering my research project to focus on how storm events may impact sea turtle disorientation events. Specifically, I will be looking at pre and post Hurricane Dorian, which hit CALO pretty hard in 2019. A recorded 9 foot storm surge approached CALO’s barrier islands from the sound side, creating multiple breaches, flattening of sand dunes and beach slope, and even some large inlets that make sections of the islands impassable.

Pre and Post Hurricane Dorian photos focused on Long Point Cabins, my current home base for field work on North Core Banks (Image Credit: National Parks Traveler, 2019).
Video showing a newly created inlet after Hurricane Dorian. Also provides as a great example to how flat the area is. This area is also prone to over wash, which can be damaging to incubating sea turtle nests.

While some of the breaches have begun to close naturally, the islands have a long time before dunes begin to recruit pioneer species and rebuild natural slope and coverage. My research project will be focusing on sea turtle disorientation events from the 2020 season, the first season after Hurricane Dorian. I will be using GIS to map out areas where dunes and potential shorelines no longer exist, potentially minimizing habitat use for nesting sea turtle mothers. I am interested in seeing if sea turtle disorientation events occurred in areas where dunes are no longer present or the beach is not as sloped. I also would like to incorporate a light pollution layer to see if areas that have minimized dune coverage allow light pollution from the mainland to penetrate to the islands better. I am really excited to learn more about this dynamic ecosystem as I begin to work on my research project!

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