Coastal environments provide critical ecosystem services but experience a number of threats including marine debris and abandoned beach equipment. To address this threat, municipalities have begun enacting policy measures such as Leave No Trace ordinances. The impact of these ordinances on coastal species management has not yet been established. To evaluate the effectiveness of Leave No Trace ordinances in coastal species management, sea turtle crawl distribution, nesting success, and the frequency of obstructed crawls pre- and post-ordinance at a loggerhead sea turtle Caretta caretta nesting beach in Alabama, USA, were compared between 3 treatment groups: (1) Gulf Shores and Orange Beach with new Leave No Trace ordinances enacted in 2016, (2) Fort Morgan with no ordinance, and (3) the Bon Secour National Wildlife Refuge (NWR) and Gulf State Park with Leave No Trace ordinances but no resident human population. The ordinance had no significant effect on crawl distribution or nesting success across the study site post-ordinance. However, the frequency of obstructed crawls in populated areas declined by 18.1% with the ordinance. The presence of a resident population was a more significant driver of obstructed crawls than the ordinance, as the Bon Secour NWR and Gulf State Park had fewer obstructed crawls than either populated treatment. With time and increased compliance, Leave No Trace ordinances may have the potential to improve coastal species management and increase coastal ecosystem services through reduced marine debris entanglement and ingestion, reduced physical damage to the environment, and increased tourism revenue and environmental education.

Full reference:
​Ware, M., Fuentes M.M.P.B., (2020). Leave No Trace ordinances for coastal species management: influences on sea turtle nesting success. Endangered Species Research 41,197-207.

Check out our new article:
Drobes, E. M., Ware, M., Beckwith, V. K.,  Fuentes, M. M. P. B. (2019). Beach Crabbing as a Possible Hindrance to Loggerhead Marine Turtle Nesting Success. Marine Turtle Newsletter, 159, 1-4.

After spending previous seasons looking at the exposure of marine turtle nesting beaches to different types of coastal modifications (Kristen's 2017 Field Work ), this year Kristen Sella is looking at the quality of marine turtle nesting habitat adjacent to a specific type of coastal modification: coastal armoring. Her specific focus is areas of beach between seawalls where managers have managed to maintain a small area of nesting beach known as an artificial or urban pocket beach. It is unknown if these areas provide suitable habitat or how likely they are to be used by marine turtles. To address this, this summer she identified pocket beaches using aerial imagery on the beaches throughout the state of Florida. She then traveled around the state to ground truth a portion of these pocket beaches and collected data on each beach including slope, elevation and sand properties. This information will be compared to control beaches at adjacent armoring as well as nearby natural beaches. Kristen Sella is  finishing up the last of her site visits and the next steps for this project will include sand analysis in the laboratory to include moisture content and sand grain size analysis. Final steps will include using a wave runup model to assess the likelihood of the pocket beaches to be inundated under high tide or storm conditions and a comparison of nesting data where available from local marine turtle permit holders.
 
This project was funded by a grant awarded from the Sea Turtle Grants Program. The Sea Turtle Grants Program is funded from proceeds from the sale of the Florida Sea Turtle License Plate. Learn more at www.helpingseaturtles.org

Sea turtle eggs are heavily infuenced by the environment in which they incubate, including efects on hatching success and hatchling viability (hatchling production). It is crucial to understand how the hatchling production of sea turtles is infuenced by local climate and how potential changes in climate may impact future hatchling production. Generalized Additive Models were used to determine the relationship of six climatic variables at diferent temporal scales on loggerhead turtle (Caretta caretta) hatchling production at seventeen nesting beaches in Bahia, Espirito Santo, and Rio de Janeiro, Brazil. Using extreme and conservative climate change scenarios throughout the 21st century, potential impacts on future hatching success (the number of hatched eggs in a nest) were predicted using the climatic variable(s) that best described hatchling production at each nesting beach. Air temperature and precipitation were found to be the main drivers of hatchling production throughout Brazil. CMIP5 climate projections are for a warming of air temperature at all sites throughout the 21st century, while projections for precipitation vary regionally. The more tropical nesting beaches in Brazil, such as those in Bahia, are projected to experience declines in hatchling production, while the more temperate nesting beaches, such as those in Rio de Janeiro, are projected to experience increases in hatchling production by the end of the 21st century.

Full reference: Montero, N., P. S. Tomillo, V. S. Saba, M. A. G. dei Marcovaldi, M. López-Mendilaharsu, A. S. Santos, and M. M. P. B. Fuentes. 2019. Effects of local climate on loggerhead hatchling production in Brazil: Implications from climate change. Scientific Reports 9:8861.

Multi-species conservation strategies can be useful to maximize allocation of resources. To effectively plan for multi-species management practices, it is important to have a robust understanding of the variability in the spatial and behavioral ecology of sympatric species. To address this in the context of marine turtles, this study explored fine-scale habitat use by three sympatric species [juvenile green turtles (Chelonia mydas), Kemp’s ridley turtles (Lepidochelys kempii) and loggerhead turtles (Caretta caretta)] in a foraging area near Crystal River, Florida, United States. By combining sighting surveys and satellite tracking methods, we found that the distribution of the three species of marine turtles in this region overlapped both in space and time. We also observed differences in the fine-scale location of hotspots and in-water behavior among species, with some degree of apparent habitat partitioning. Habitat partitioning was particularly evident when assessing the diving and surfacing behavior of tracked turtles, with some degree of differentiation in diel diving patterns, particularly depths utilized during daytime/nighttime and the dive/surface duration. Our study provides ecological baseline data on the spatial overlap, habitat use and behavior of three sympatric marine turtle species, which can inform future management strategies at nearshore marine habitats in the Northeastern Gulf of Mexico.

Full reference: 
Wildermann, N.E., Sasso, C.R., Stokes, L.W., Snodgrass, D.,  Fuentes, M.M.P.B. (2019). Habitat use and behavior of multiple species of marine turtles at a foraging area in the Northeastern Gulf of Mexico. Frontiers in Marine Science. 6, 155. ​

The environment and climate in which sea turtle eggs incubate affects how successful and viable hatchlings are. Therefore, it is crucial to understand how local climate impacts sea turtle hatchling production as well as how potential changes in climate may impact future hatchling production. In this study, we investigated the effects of five climate variables at different temporal scales on loggerhead sea turtle (Caretta caretta) hatchling production from North Florida, USA. Humidity, air temperature, and accumulated precipitation were the main climatic drivers of hatchling production, while sea surface temperature and wind speed did not demonstrate to have strong effects. Climate projections show air temperatures increasing at the nesting beaches throughout the 21st century, while precipitation and humidity projections vary between sites and projection scenarios. Due to the temperate nature of these nesting beaches, increases in hatching success for nests that incubate undisturbed (not affected by depredation and storm-related impacts) are projected for this region by 2100. This study demonstrates how different climate variables and their interactions can have a determining effect on an important marine species.

Reference: Montero, N., Ceriani, S.A., Graham, K., Fuentes, M. M. P. B. (2018). Influences of the local climate on loggerhead hatchling production in North Florida: Implications from climate change. Frontiers in Marine Science, 5, 262​

Species’ foraging choices influence their somatic growth rates, age at maturity, and time spent in vulnerable early life stages. Thus, differences in population demographics are often attributed to variability either in diet type, quality, and/or quantity ingested. Knowledge of diet selection, though currently limited, can enhance our understanding of the roles of marine turtles in marine ecosystems and, at a finer scale, elucidate how nutrition and diet influence their growth and productivity. To investigate this relationship, we coupled stable isotope analysis with a diet preference index to provide insights into the selection and plasticity of juvenile green turtle Chelonia mydas diet. The study was conducted at 2 sites (Bonefish Hole and South Bimini) in Bimini, Bahamas, in 2016. Habitat surveys were conducted to gather habitat data and determine resource availability. A dichotomy in diet was found between the sites: at Bonefish Hole, turtles exhibited a more generalist omnivorous diet, selecting for sessile filter feeders and green algae, whereas turtles in South Bimini had a more specialist herbivorous diet, primarily consuming seagrasses and selecting for red algae, when available. The foraging dichotomy found in this study expands our understanding of the spatial differences in green turtle biology in the Bahamas and provides novel information for turtle foraging in Bimini. Knowledge about differences in intra-specific diet, with a focus on diet selection and potential drivers, can shed light on the factors that influence critical life history traits and ultimately inform species management.

​Gillis, A. J., Ceriani, S. A., Seminoff, J. A., Fuentes, M. M. P. B. (2018). Foraging ecology and diet selection of juvenile green turtles in the Bahamas: insights from stable isotope analysis and prey mapping. Marine Ecology Progress Series, 599, 225-