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The impacts associated with global climate change (e.g., sea-level rise, tropical storms, and warming temperatures) are expected to alter predator–prey interactions, foundation species, and plant community structure in coastal ecosystems. While the complex dynamics of these habitats have been examined under future climate predictions, few ecosystem models incorporate influences from fauna, such as the diamondback terrapin, the only estuarine turtle native to North America. This review examines the impacts of climate change on diamondback terrapins (Malaclemys terrapin) and the role that terrapins play as higher trophic level predators and keystone species in driving the dynamics of these ecosystems. We also review the potential implications of changes to terrapin populations on coastal ecosystems as a conservation challenge and suggest solutions to advance our understanding of those complex systems. Because of their role as a keystone and area-sensitive species that helps maintain healthy coastal habitats by foraging on herbivorous periwinkle snails, alterations to terrapin life history from climate change are expected, which could have significant impacts to the conservation of coastal habitats. Life history alterations could occur due to individual stressors, such as warming temperatures altering terrapin sex ratios. However, because of the complexity of these coastal systems, these stressors could also act additively or synergistically. Inclusion of faunal taxa such as the diamondback terrapin in modeling efforts examining climate change impacts to coastal ecosystems would better represent the complexity of these habitats thereby providing a more comprehensive evaluation of the entire ecosystem, resulting in more effective conservation strategies. [ABSTRACT FROM AUTHOR]

Coastal habitats are some of the most imperiled due to climate change and anthropogenic activities. As such, it is important to understand population dynamics of the species that may play a role in regulating coastal systems. Diamondback terrapins in Northwest Florida have been understudied, which has resulted in a gap in our knowledge for this region. To help fill this gap, we conducted a capture-mark-recapture study in St. Joseph Bay, Florida, from 2018 to 2021. Overall, we captured 518 individuals, including 146 recaptures, and we used several modeling frameworks to estimate apparent survival, recapture probability, population entrance, and population size. Our estimates of apparent survival were relatively low, especially for adult males (0.77) and adult females (0.83), but there is a considerable amount of uncertainty around our estimates. Our models indicated that the super-population consists of 1122 individuals (971–1327 95% CI), and the population is comprised of more adult males (753; 665–866 95% CI) than adult females (102; 85–130 95% CI) and juveniles (267; 221–331 95% CI). Estimates of population entrance varied by year throughout our study duration. This study is the first to document a Malaclemys terrapin population in this region of Florida, and we recommend long-term monitoring in order to gain inferences for the management of this declining coastal species. [ABSTRACT FROM AUTHOR]

Multi-species assemblages can help identify key resources in their habitat by evaluating how they are partitioning their resources. Here we used the isotopic niche of loggerhead, Kemp's ridley, and green sea turtles to assess their ecological niche within a Gulf of Mexico bay. Additionally, we assessed temporal and size-class variation in their diets by comparing the δ13C and δ15N values over various capture years and size classes. Based on the isotopic niche overlap results, interspecific competition occurs among loggerhead, Kemp's ridley, and smaller green turtles. Green turtle and Kemp's ridley diet varied by size class, while Kemp's ridley diet also varied temporally. The three species partition resources by selecting different preferred diet items, although some overlap in diet, including between the herbivorous (green) and carnivorous (Kemp's ridley, loggerhead) species, appears to occur. The high quality of this habitat may allow species co-existence and population recovery despite the possible use of shared resources. [ABSTRACT FROM AUTHOR]

The diamondback terrapin (Malaclemys terrapin) is a small estuarine turtle distributed along the Atlantic and Gulf Coasts of the USA that is threatened by drowning in crab pots, road mortality, exploitation in the pet trade, and habitat loss. Little is known about the movement patterns and home ranges of these turtles, particularly along the U.S. Gulf of Mexico coast. Satellite tags were deployed on two adult female terrapins captured at two distinct sites in Northwest Florida. A first-difference correlated random walk approach was used to determine distances traveled and estimate home range for each individual. The two terrapins were tracked for 146 and 147 days, and the total distance traveled for each terrapin was 70.1 km and 723.0 km, respectively. The maximum distance moved from capture location was 11.3 km and 49.6 km. Home ranges here were much larger than those previously reported in other studies. The movements we documented were greater than expected and indicate habitat protection for this species may need to be expanded to incorporate more distant foraging sites. [ABSTRACT FROM AUTHOR]

Natural disturbances are an important driver of population dynamics. Because it is difficult to observe wildlife during these events, our understanding of the strategies that species use to survive these disturbances is limited. On October 10, 2018, Hurricane Michael made landfall on Florida's northwest coast. Using satellite and acoustic telemetry, we documented movements of 6 individual turtles: one loggerhead sea turtle, one Kemp's ridley sea turtle, three green sea turtles and one diamondback terrapin, in a coastal bay located less than 30 km from hurricane landfall. Post-storm survival was confirmed for all but the Kemp's ridley; the final condition of that individual remains unknown. No obvious movements were observed for the remaining turtles however the loggerhead used a larger home range in the week after the storm. This study highlights the resiliency of turtles in response to extreme weather conditions. However, long-term impacts to these species from habitat changes post-hurricane are unknown. [ABSTRACT FROM AUTHOR]