ORCID

0000-0002-2430-0863

Keywords

sea turtle, phenology, reproductive success, ACNWR, long-term trends, conservation

Abstract

The UCF Marine Turtle Research Group (MTRG) has monitored sea turtle nesting along the Brevard County, Florida coastline for over 40 years, yielding one of the world's longest continuous sea turtle reproductive datasets. These data offer key demographic insights for conservation and species recovery assessments. Given climate change’s worsening effects, it is critical to analyze long-term trends in hatchling emergence success and phenology, which impact reproductive output, population growth, and hatchling dispersal. Here I compare the long-term reproductive output trends of loggerhead (Caretta caretta), green (Chelonia mydas), and leatherback (Dermochelys coriacea) sea turtles from the densely nested Archie Carr National Wildlife Refuge (ACNWR), over a turtle-generation time frame (20-40 years). With potential phenological shifts occurring due to climate change, hatchling emergence success and timing may be at risk due to changes in exposure to seasonal and temporal conditions over time. My two primary objectives were: 1) to assess changes over time (1988-2023) in hatchling reproductive output in all three species in relation to abiotic and biotic influences, and 2) to determine if there have been changes over time (2001-2023) in hatchling emergence phenology across the three species. Bayesian Zero-Inflated and Generalized Additive Models were used to assess my objectives. Long-term hatchling emergence success has remained stable, though species-specific differences exist. Water disturbances and raccoons (Procyon lotor) had the most severe impacts, significantly increasing nest failure in green turtles and loggerheads, while leatherbacks were less affected. Median emergence dates shifted later for loggerheads and green turtles, while shifting earlier for leatherbacks. The hatchling emergence season lengthened for loggerheads and leatherbacks but shortened for green turtles. These findings provide essential baselines for long-term emergence success and hatchling emergence phenology, helping to assess species trends and understand how sea turtles may be adapting to the challenges of climate change.

Completion Date

2025

Semester

Spring

Committee Chair

Mansfield, Katherine L.

Degree

Master of Science (M.S.)

College

College of Sciences

Department

Biology

Identifier

DP0029372

Document Type

Dissertation/Thesis

Campus Location

Orlando (Main) Campus

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