After spending the week on-site at Buck Island Reef National Monument (BUIS), my time as a SIP Fellow is almost over! Before I go, I’d like to finish sharing the results from the primary objective of my project: Conduct a baseline assessment of the critically endangered hawksbill turtle nesting aggregation at BUIS.

Before I “geek out” about the results from my summer spent wrangling data, let me explain how I addressed this objective. In a nutshell, I evaluated whether abundance (annual counts of females and nests) and reproductive parameters have changed over the last 31 years (1988-2019). Reproductive parameters included hatch success (proportion of eggs that hatched per nest), emergence success (proportion of hatchlings that reached the beach surface per nest), clutch size (# eggs per nest), hatchling production (# individuals produced per nest), and average female body size (length of the carapace or “shell”). Assessing temporal trends in these parameters provides important information about the status of the female aggregation and nest success in the park.

Prior to the establishment of the Buck Island Sea Turtle Research Program in 1988, almost all hawksbill nests documented in the park during the early ‘80s were either predated by invasive mammals (rats and mongoose) or poached by humans. Since the program’s inception, nesting hawksbills have made a dramatic recovery at BUIS – going from 12 females documented in 1988, to 60-80 individuals at present. That may not seem like a lot to some, but for an animal that takes 30 years to reach maturity, that’s a major comeback! Although this is a significant conservation achievement for the park, project results indicate that female abundance has stabilized over the last 13 years, and with this trend comes questions about what’s next for the park’s sea turtle management plan. Results from my project suggest a couple of things that may be contributing to this trend: 1) Hawksbills have increased nesting activity beyond the park boundary (discussed in my previous post); and 2) Female recruitment and reproductive productivity may be declining.

The impacts of climate change — including warming seas, sea-level rise, increased storm frequency — pose a significant threat to the persistence of sea turtle populations worldwide, and have been linked to decreases in turtle productivity (e.g. growth rates) and loss of quality nesting and foraging habitats. Therefore, it was no surprise to find that average female body size and clutch size (# eggs per nest) for BUIS hawksbills has significantly declined over the last few decades. Smaller turtles produce fewer eggs per nest, which could eventually affect the number of hatchlings contributed to the population, particularly as female abundance stabilizes and fewer first-time nesters are documented (aka fewer females recruit to the population and/or take longer to reach maturity). Fortunately, there was no temporal trend in hatch success, emergence success, or hatchling production throughout the duration of the project — but the combination of smaller clutches and other impending threats (e.g. nest erosion by frequent storms, female-biased clutches) could change that.

What do these results mean for hawksbill conservation at BUIS? First off, changes in female abundance and decreased body size suggest that the productivity of the population may be declining, thus reinforcing the need for continued monitoring. The next step for NPS managers is to diagnose the factor(s) behind the trends reported from my project, so appropriate management action can be implemented. This can be accomplished by evaluating if population demographics are changing, including growth rates, survivorship, clutch frequency (# nests per female during a single breeding season), and reproductive output. Sounds like a great project for the next SIP fellow!

So to close my final post, I’d like to express a huge thank you to NPS at BUIS for this fantastic opportunity to gain essential skills for pursuing a career as a federal marine ecologist, and contribute to the management of sea turtles in the park. I am also grateful to the SIP and ESA coordinators for offering such incredible opportunities for aspiring scientists and resource managers.

Want to hear more about my results, and other SIP projects from this summer? Come see my virtual presentation on August 2nd, between 2:30-4:45. You can register for the webinar here.

If you have any questions about my project or would like to learn more about what I do as a marine ecologist, please contact me (alexandra.gulick@nullufl.edu), follow along on Twitter, or visit my personal website (see Curriculum Vitae).

As mentioned in my previous post, one of the primary components of my project is to conduct a baseline assessment of the hawksbill turtle nesting population at BUIS using 33 years of data collected by the NPS Buck Island Sea Turtle Research Program. Project results will provide resource managers, along with local conservation agencies and the Virgin Islands Hawksbill Recovery Action Plan Working Group, with products that will guide future management practices for hawksbill turtles in the Virgin Islands. My project results clearly indicate a dramatic recovery of the hawksbill nesting population at BUIS since the 1980s — a remarkable success that’s attributable to the establishment of long-term monitoring and research programs, enforcement of conservation laws, successful eradication of invasive predators on the nesting beach, local education and outreach, and community support. However, the population appears to have stabilized in recent years, and with that trend comes many questions of what the future holds for this critically endangered species in the park and surrounding waters (stay tuned!). One aspect that is clear, is that hawksbills have recently been relying more heavily on the nesting beach habitat available on the neighboring island of St. Croix (Note: sea turtles lay multiple nests in a single season, sometimes on more than one beach).

Successful conservation of sea turtles at BUIS would not be possible without the support from the local community on St. Croix. One of the biggest things I have come to appreciate from my experience as a SIP Fellow is just how important it is to have that support, and how integral it is for resource managers and scientists to share the success of conservation programs with the community.

The “spill-over” of hawksbill nests on to St. Croix beaches – most of which are more developed and/or unmonitored – is a conservation achievement that comes with new challenges that will greatly depend on community support to address. As a SIP Fellow, I hope to contribute to sharing the success of the park’s sea turtle program with the public and raise awareness for the increasing presence of nesting turtles on St. Croix beaches, by conducting workshops on nesting beach monitoring methods for local students and community volunteers. I am beyond excited to visit the park later this month and engage with the public during these workshops!

Stay tuned for further updates on sea turtles at BUIS! You may also find me on Twitter (@AlexandraGulick), Instagram (@alexandra.gulick), or visit my website.

This summer, I am very excited to be a Scientists in Parks Fellow (SIP) for the National Park Service in St. Croix, U.S. Virgin Islands. NPS manages three parks in St. Croix: Christiansted National Historic Site, Buck Island Reef National Monument (BUIS), and Salt River Bay National Historical Park and Ecological Preserve; all of which have their own unique natural and cultural resources. As a SIP Fellow, I will be working most closely with natural resources at BUIS.

BUIS is a marine protected area off the coast of St. Croix, U.S. Virgin Islands that hosts a variety of tropical marine ecosystems (e.g. coral reefs, seagrass meadows, deep-water habitats, coastal beaches and tropical dry forests) and threatened / endangered species. BUIS has one of the most pristine elkhorn-coral barrier reef ecosystems in the Caribbean, and is one of few national parks that is almost entirely underwater. The park’s biological diversity and complexity offers incredible opportunities for public recreation, education, and scientific research. A hallmark of the park’s natural resource management initiative is the Buck Island Sea Turtle Research Program (BISTRP). BUIS provides critical nesting and / or foraging habitat for four sea turtle species, including hawksbill, green, leatherback, and loggerhead. The BISTRP has monitored sea turtles at BUIS since 1987, and has been recognized as one of the most intensive and successful sea turtle monitoring programs in the world, particularly for hawksbill turtles (see photo).

For my SIP project, I am analyzing 33 years of monitoring data to provide a baseline assessment for the nesting aggregation of hawksbill turtles at BUIS. This assessment will assist resource managers in adapting management plans to ensure the continued conservation success of this endangered species in the park and throughout the U.S. Virgin Islands. The majority of my fellowship will be conducted remotely from my location in Gainesville, Florida, but I will be visiting the park in July to run a workshop on sea turtles for local high school students participating in the Youth Oceans Explorers program.

Stay tuned this summer for further updates on sea turtles at BUIS! You may also find me on Twitter (@AlexandraGulick), Instagram (@alexandra.gulick), or visit my website.

Want to know more about BUIS? Check out this short video for an excellent overview of the park’s history, natural resources, and its importance to sea turtle conservation in the Caribbean.