By: Nichelle Van Tassel, Master’s Student
Coastal Dune Lakes (CDL) are a rare and unique habitat found only in New Zealand, Australia, Madagascar, and along the Gulf Coast in Northwest Florida. In Florida, there are fifteen irregularly shaped, shallow lakes that stretch across 26 miles of coast in Walton County. The lakes are located behind the sand dunes and often have an intermittent connection to the Gulf of Mexico, which allows for water exchange between the Gulf and the lakes. Because the lakes are open to the Gulf at different times of year for different amounts of time, each individual lake has a unique water chemistry and likely a unique biodiversity makeup.
The lakes are currently protected by the Choctawhatchee Basin Alliance (CBA), and the Walton County local government through the Costal Dune Lakes Advisory Board. Florida Natural Areas Inventory has classified the lakes as “critically imperiled in Florida because of extreme rarity.” Although there are many policies in place to protect the lakes, very little is known about the plant and animal communities living in these habitats.
My thesis project aims to assess the fish biodiversity of the CDL using environmental DNA and metabarcoding techniques. For this project, environmental DNA refers to the DNA an organism leaves behind from lime, scales, feces, urine, etc. It is similar to crime scene DNA in that we don’t need to see the fish living in the lakes to know that they were there, just as we don’t need to see the criminal at the crime scene to know that they were there if we find their DNA. We will be using water samples to analyze eDNA for this project. We will then amplify and sequence the extracted DNA, which will give us the DNA sequence or name of our detected CDL dwelling fish.
You can read more about CDL and how you can visit them at: http://www.waltonoutdoors.com/all-the-parks-in-walton-county-florida/coastal-dune-lakes-of-south-walton/