Predicting Vulnerability of Southeastern Sea Turtle Nesting Beaches to Climate Change

Science Center Objects

Climate change may reduce the suitability of nesting and foraging habitat used by federally threatened and endangered species, like the Loggerhead sea turtle.

PROJECT COMPLETE

Predicting Vulnerability of Southeastern Sea Turtle Nesting Beaches to Climate Change

Loggerhead sea turtle

The Science Issue and Relevance: Sea-level rise (SLR), increased storminess, and altered temperature and humidity associated with climate change may reduce suitability of nesting and foraging habitat used by federally threatened and endangered species. By integrating biological, geologic, and oceanographic modeling efforts with long-term sea turtle nest data for the southeast US, our objective is to conduct a vulnerability assessment of coastal habitats representing important nesting grounds specifically for federally threatened loggerhead sea turtles (Caretta caretta). Since some of the same nesting beaches are also important for other endangered sea turtles (i.e., (http://www.gfdl.noaa.gov/climate-impace-of-quadrupling-co2) Kemp’s ridleys (Lepidochelys kempii), green turtles (Chelonia mydas), and leatherbacks (Dermochelys coriacea)), this project represents an initial vulnerability assessment of coastal nesting habitats for multiple species of national conservation significance. Loggerheads in particular have experienced recent dramatic declines in nesting numbers in the Peninsular Florida and Northern Gulf of Mexico Recovery Units (e.g., ~40% since 1998; Witherington et al. 2009). Therefore, this work directly addresses one of the recovery criteria in the recently-revised federal Loggerhead Recovery Plan (Aug. 2009: Listing Factor Recovery criterion 1.a.4., “development of a model describing the effects of sea level rise on loggerhead nesting beaches in the southeast US”.) 

Predicting Vulnerability of Southeastern Sea Turtle Nesting Beaches to Climate Change

Sea level rise impacts to sea turtle nesting beaches

Methodology for Addressing the Issue: Using previous records of whether and how loggerhead sea turtles have used southeastern US beaches for nesting, including information on elevation and reproductive success, we will forecast turtle habitat use on those same beaches in the future, based on both habitat availability and suitability. Data used to test models and statistical relationships include long-term loggerhead nesting data from the Archie Carr National Wildlife Refuge (courtesy of Indian River County and University of Central Florida), information derived from a currently funded down-scaling NCCWSC project, “LaFlorida” (USGS-Smith et al.), and historical shoreline change data that is available from a variety of ongoing or completed projects. By including time-series of biological observations (i.e., turtle nests and false crawls) with geological and climate predictors of habitat suitability, our results will pinpoint nesting beaches within the modeled domain that are likely to deteriorate due to climate change and SLR. This information can be used by managers to evaluate management options for ensuring suitable conditions for loggerhead nesting (e.g., moving nests, land acquisition).

Future Steps: In FY12 we obtained turtle data from Archie Carr NWR. In future years we aim to expand the study area to add additional study sites (i.e., Cape Romain, SC) and analyze data for nesting green turtles Chelonia mydas at Archie Carr NWR.  

Related Project(s):

La Florida (PI Tom Smith), Integration of Sea-level Rise, coastal erosion, barrier island geomorphology, and plover suitability models (PI Nathaniel Plant)

Predicting Vulnerability of Southeastern Sea Turtle Nesting Beaches to Climate Change

Archie Carr National Wildlife Refuge