UOG Sea Grant: Green sea turtle nesting, tagging records set in 2021
Sea turtle biologists from the University of Guam Sea Grant program documented two new records of green sea turtle activity on Guam shores last year.
Biologist duo Addie Ferguson and Leilani Sablan reported more than 200 nesting emergences by the endangered green sea turtle (Chelonia mydas, or haggan in CHamoru) in 2021, up from 100 to 150 emergences reported in 2019 and 2020.
Setting another record, they tagged nearly 10 nesting females in 2021, contributing to a collective 20 turtles tagged since the tagging project began in 2014.
The team conducts their research at one of Guam’s largest nesting grounds. This is made possible through a cooperative agreement between UOG, Joint Region Marianas, and Andersen Air Force Base and is aligned with JRM’s Section 10 Endangered Species Permit. The permit allows for authorized biologists to work with endangered species after having met certain experience criteria for research and species recovery purposes. The project is further supported by personnel from the 36th Civil Engineering Squadron’s environmental flight.
According to Ferguson, the particular area is popular among nesting turtles due to its seclusion and lack of development. Sea turtle nests have been reported in the location since the 1970s.
Going into a ninth recorded nesting season, Ferguson and Sablan have actively monitored nests until signs of hatching are observed. They tag nesting females during night surveys, when suitable, and examine nests to determine hatching and emergence success rates.
Ferguson said the data will help them gain a better understanding of green sea turtle nesting population trends and that they hope to see the trend continue in the years to come.
This year, they anticipate deploying 30 temperature data loggers within the nests, which will allow them to better understand the hatchlings’ sex ratio. Further, they intend to satellite tag two nesting females to more clearly determine the species’ migration patterns.
Understanding the importance of community awareness and support in their research journey, the team conducts sea turtle outreach activities throughout the island with presentations for students of all grade levels and exhibits at various events.
“Being local and knowing haggan are culturally significant to our people makes it feel like I’m fulfilling an inherent responsibility of helping to preserve this species for future generations of CHamoru,” Sablan said. “It’s like taking care of something our ancestors passed on to us, and I’m really happy to be putting in the work.”
Ferguson is encouraged to contribute to what limited information is available about green sea turtles in the region.
“I’m thrilled to be continuing my research with Sea Grant. There is still so much to learn and many aspects to study regarding sea turtles in Guam, especially. There is little published research on sea turtles, specifically in the Marianas. We are constantly learning more about our haggan population here, and that makes me excited for what the future of sea turtle research will look like in Guam for decades to come,” Ferguson said.
Photos courtesy of University of Guam. These photographs were taken in connection with research authorized under the Andersen Air Force Base Recovery Permit TE-84876A-1 and funded by the Department of the Navy on behalf of Joint Region Marianas.