Defense Date


Document Type


Degree Type

Master of Science

Degree Name

Marine Science

First Advisor

Dorothy Ellen Renegar, Ph.D.

Second Advisor

David Kerstetter, Ph.D.

Third Advisor

Kirk Dotson, Ph.D.

Fourth Advisor

David Gilliam, Ph.D.


restoration, predation, coral, PHA, exclusion device, parrotfish, biodegradation


Florida's coral reefs are in a state of near-constant degradation concomitant with ever-increasing coastal development and associated anthropogenic impacts. Government agencies, non-profits, and concerned citizens have spent significant time and resources combating these negative impacts. One primary method of mitigating damage to coral reefs is to transplant corals onto degraded reefs using corals that have been grown in nurseries. While many challenges of reef restoration have been overcome, parrotfish predation on freshly transplanted corals persists as a significant issue. Parrotfish are recognized as an essential species on healthy reefs but can also hinder reef restoration efforts by biting young, newly transplanted corals. This project endeavored to reduce the labor and costs of transplant operations by reducing the impacts of predation on transplanted corals. To minimize predation on newly transplanted coral fragments, this project utilized a protective structure that coral fragments are attached to before transplant.

Three novel prototype parrotfish exclusion devices were tested in-situ; these prototypes deemed “Coral Castles,” have a barrier of biodegradable polyhydroxyalkanoate (PHA) tubes integrated with a concrete base. Two separate fragment transplanting trials, one using Porites astreoides and one using Orbicella faveolata, were monitored for several months. The Coral Castle prototypes were found to significantly reduce the number of bites incurred by transplanted corals as well as significantly reduce dislodgment, improving survivorship. The in-situ biodegradation rate of PHA, described as mass loss, is quantified in a separate experiment. The end goal was to produce an easily secured tile that does not obstruct coral growth, require maintenance, or allow parrotfish to easily predate upon the coral.


Experimentation and collection of corals legally conducted through the following Special Activities Licenses

  • SAL-23-2515-SCRP
  • SAL-20-1727-SCRP
  • SAL-22-2482-R



Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.