Date of Award
Fall 11-10-2025
Document Type
Dissertation
Publication Status
Version of Record
Submission Date
December 2025
Department
Biological Sciences
College Granting Degree
Charles E. Schmidt College of Science
Degree Name
Doctor of Philosophy (PhD)
Thesis/Dissertation Advisor [Chair]
Matthew J. Ajemian
Abstract
Elasmobranchs (sharks, skates, and rays) are among the most threatened vertebrate groups due to biological and anthropogenic pressures. Their low fecundity, late maturity, and slow growth make them susceptible to overfishing, habitat degradation, and habitat loss. A trade-off for the low fecundity is the investment in juvenile survival through the use of nurseries, which can play a crucial role in population recovery. However, these nurseries, often located in shallow coastal areas, are increasingly degraded by coastal development and are frequently utilized for human activities, leading to conflicts between humans and wildlife.
This study combined acoustic telemetry, phycotoxin analysis, and a citizen science approach to provide information for the conservation of the globally endangered whitespotted eagle ray (Aetobatus narinari) in Florida and beyond. First, this study aimed to identify nursery areas for A. narinari in Florida to aid with population recovery (Chapter 1). Moreover, this study gathered information on the uptake of phycotoxins (Chapter 2) and assessed negative interactions with rays in the shellfish aquaculture industry (Chapter 3). Acoustic telemetry supported the role of Sarasota Bay and the Indian River Lagoon (IRL) as nurseries with young-of-the-year rays remaining in these areas for extended periods. Phycotoxin analysis confirmed the uptake of phycotoxins across life stages and tissues, highlighting dietary exposure as a primary pathway. A survey analysis confirmed the perception of sharks and rays as a safety threat to Florida’s shellfish farmers. Stingrays and cownose rays were reported as the primary species interacting with the gear, while interactions with A. narinari remained unclear. Captive trials demonstrated a 29% reduction in feeding success with the Sharkbanz Zeppelin and eliminated bag damage, showing a promising avenue to explore non-lethal deterrents as a mitigation strategy.
This study provided evidence for the use of Sarasota Bay and the IRL as eagle ray nurseries, highlighting harmful algal blooms (HAB) as a key conservation challenge. These findings underscore the need to accelerate research on HAB mitigation strategies to preserve ecologically important estuaries sustaining eagle ray populations and human activities. Equally important is the exploration of nonlethal deterrents in shellfish aquaculture to foster coexistence between rays and humans.
Recommended Citation
Rojas, Ariadna Corzo, "CONSERVATION ECOLOGY OF THE WHITESPOTTED EAGLE RAY (AETOBATUS NARINARI) IN FLORIDA’S COASTAL WATERS" (2025). Electronic Theses and Dissertations. 221.
https://digitalcommons.fau.edu/etd_general/221