Grant: 22-029R
Project Title: Investigating baseline demographics and inter-nesting habitat for a globally important loggerhead rookery: Year 3
Project Manager: Sarah Hirsch
Organization: Loggerhead Marinelife Center (Non-Profit Organization)
Grant Amount: $36,435.00
Completion Date: 2023-04-24
Summary: Southeastern Florida is a critical breeding ground for loggerhead sea turtles (Caretta caretta). While nest counts reveal that Palm Beach County hosts the highest density of loggerhead nesting the in state of Florida, little research has evaluated key life-history traits and habitat use of breeding loggerheads in this area. Clutch frequency refers to the number of nests a female sea turtle deposits within one breeding season and serves as a key measure of a female's total reproductive output. By satellite tracking nesting loggerheads from their first nest of the season, this study aims to provide an accurate clutch frequency estimate. In addition, nest site fidelity and inter-nesting home range estimates will be evaluated to understand the space use of breeding loggerheads in southeastern Florida. Elucidating in-water hotspots is imperative for developing effective conservation strategies aimed at loggerhead population recovery.
Results: Eleven satellite tags were successfully deployed (including the 7 Wildlife Computers SPLASH tags purchased with funds from this grant) on nesting loggerhead sea turtles during the 2022 nesting season. Ten tags were deployed between April 14 and April 26. One tag was deployed on May 17 when a turtle satellite tagged in 2021 was re-encountered (details below). Using an Argos goniometer, we were able to re-encounter seven turtles on subsequent nesting events (range: 1-4 encounters). During the 2022 season, we re-encountered two females satellite tagged in previous years. The first female was satellite tagged in 2020 (STG #20-016R). Her satellite tag was still attached, although badly damaged and no longer transmitting. The tag was removed and recovered. Unfortunately, we did not have a spare tag, so she was not re-satellite tagged. While trying to find this turtle on another nesting event to get a second satellite tag on her, we encountered another turtle we had originally satellite tagged in 2021 (STG #21-021R). This female had shed her 2021 satellite tag, but we were able to deploy an extra tag (11th tag deployed on May 17 as stated above) provided by Dr. Simona Ceriani. This turtle was tracked back to the Mid-Atlantic Bight, the same foraging area she went to after the 2021 nesting season. Tracks and data from 27 loggerheads, including 21 tags provided by the STGP (STG 20-16R, STG #21-021R, and STG #22-029R), were presented at the 2023 Southeast Regional Sea Turtle Symposium. Our goal is to tag a total of 50 individuals before publishing our findings in a scientific journal.