Date of Award
1-2025
Document Type
Thesis
Degree Name
Master of Science (MS)
College/School
College of Science and Mathematics
Department/Program
Marine Biology and Coastal Sciences
Thesis Sponsor/Dissertation Chair/Project Chair
Colette Feehan
Committee Member
Paul Bologna
Committee Member
Matthew Schuler
Abstract
The sea urchin Diadema antillarum is a key coral reef grazer that remains functionally extinct on many Caribbean reefs following a mass mortality event in 1983–84. In 2022, another widespread mortality event, likely caused by a scuticociliate parasite, again decimated D. antillarum at reefs across the Caribbean. Understanding the population-level impacts of this recent epizootic will be important for coral reef conservation efforts. This study examines multi-year larval settlement data from the Florida Keys to determine if the 2022 mortality event reduced larval settlement. Larval settlement was assessed monthly at three long-term monitoring sites (Delta Shoal, Tennessee Reef, and Pickles Reef) using artificial turf plates, spanning three periods: 4.5 years before, 5 months during, and 2 years after the 2022 epizootic. Zero-inflated Poisson regression analysis indicated no significant change in settlement rates across these time periods. Although many zero values were observed, peaks in settlement also occurred, reaching a mean of up to 40 settler m⁻² in a given month. However, the magnitude and frequency of settlement pulses required for population recovery remain unknown. Nonetheless, the findings suggest that the abundance and fecundity of the source population(s) were not severely impacted by the 2022 epizootic. While other potential influences on settlement, such as predation, were not evaluated, these results may offer some optimism for managers working to restore grazing function on Florida’s reefs through D. antillarum population enhancement.
File Format
Recommended Citation
Albrecht, Jason, "No detected signal of the 2022 epizootic from multiannual Diadema antillarum settlement data in the Florida Keys" (2025). Theses, Dissertations and Culminating Projects. 1455.
https://digitalcommons.montclair.edu/etd/1455
