Defense Date
8-7-2026
Document Type
Thesis
Degree Type
Master of Science
Degree Name
Marine Science
First Advisor
Andrew Bauman
Second Advisor
Fraser Januchowski-Hartley
Third Advisor
Margaret Malone
Keywords
Predation Risk, Coral Reefs, Giving-up Density, Foraging Behavior, Fishing Pressure, Marine Protected Areas
Abstract
Predation risk influences foraging decisions by altering how individuals balance energy gain and predator avoidance. In marine systems, fishing pressure may simultaneously reduce natural predator populations while imposing anthropogenic predation risk. Marine protected areas provide a valuable framework in which multiple sources of predation risk can be compared.
Chapter 1 reviews the ecology of fear in coral reef ecosystems and introduces the use of the giving-up density technique as a metric to measure predation risk in foraging under natural systems. Chapter 2 applies this framework to assess risk perception across management categories in the central Philippines, influenced by both human and natural sources of risk. Chapter 3 discusses the broader implications of results found in Chapter 2 suggesting the use of GUDs as tool to quantify chronic anthropogenic risk.
Using GUD food patches and video recordings at the patches, Chapter 2 evaluated patch design performance, GUDs and habitat-mediated risk responses, predator and forager community context, individual temporal foraging dynamics, species and size-structured foraging patterns, and antipredator behaviors (vigilance, grouping). Results uncovered significantly lower GUDs within protected management despite substantially higher predator abundances, while forager abundance remained similar among management categories. Temporal patterns in bite rates and inspection behavior differed among management categories, group-foraging probabilities were greatest within protected reefs, and habitat-mediated risk responses occurred exclusively within Fished reefs. Collectively, these findings suggest that predator source (i.e., humans or natural) may shape foraging decisions uniquely and suggests the potential ability of GUD to quantify chronic anthropogenic risk within coral reef ecosystems.
NSUWorks Citation
Eleni Lyons. 2026. Evaluating Fish Risk Perception Across Marine Reserves Through the Use of GUDs. Master's thesis. Nova Southeastern University. Retrieved from NSUWorks, . (251)
https://nsuworks.nova.edu/hcas_etd_all/251.