Loggerhead sea turtles (Caretta caretta) that nest in Everglades National Park are most prevalent on Cape Sable, a remote coastal landmass on the western side of the park that is one of the last remaining nesting locations in Florida not directly disturbed by human activity. However, this nesting population faces threats from depredation and overwash and inundation from coastal erosion, which has been exaggerated from anthropogenic influence. Nesting surveys were conducted during 2014 and 2015 nesting seasons, nest inventories were completed on each confirmed nest, threats were ranked using scope and severity measures and the results from each nesting season were totaled and analyzed using statistics and spatial analyses. This data was also compared with previous studies. In 2014, 234 crawls were observed where 99 of those crawls were confirmed as nest sites and in 2015, 237 crawls were observed where 80 of those crawls were confirmed as nest sites. Forty-four of the total 99 nests in 2014 were impacted from depredation mainly from raccoons (Procyon lotor marinus) and 8 of the total 80 nests in 2015 were impacted from depredation mainly from fire ants (Solenopsis invicta). There were no confirmed overwashed or inundated nests in 2014 and there were 3 confirmed overwashed and inundated nests in 2015. Depredation abundance dropped from 44% in 2014 to 10% in 2015 and overwash and inundation abundance was 0% in 2014 and 3.8% in 2015. Overall depredation impact was ranked as “High” and overall overwash and inundation was ranked as “Low” for 2014 – 2015 nesting seasons. However, these ranks may only represent each threat’s short-term impact and long-term data collection and analysis will provide further information on each threat’s impact. The rate of coastal erosion on Cape Sable is increasing due to an altered hydrologic regime, climate change and rising seas, extreme weather events and tidal surges, and this may significantly impact sea turtle nesting activity in Everglades National Park in the future. Nest relocation is one potential management strategy to help mitigate the impacts from depredation and overwash and inundation and long-term spatial analysis of nesting activity may help determine potential nest relocation sites on Cape Sable where threat impacts are low.
Pechtl, Charlotte, "Cape Sable threat assessment: Analyzing the threats to Cape Sable’s loggerhead sea turtle (Caretta caretta ) nesting population in Everglades National Park" (2016). Internship Reports (Restricted). 76.
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