Impacts of Reef Fish Length on Foraging Radius: Exploring Behavioral Patterns Within a Patch Reef Ecosystem

Author

Kilia Brawand, Utah State University

Date of Award

5-2025

Degree Type

Thesis

Degree Name

Departmental Honors

Department

Biology

Abstract

Reef fish exhibit various behaviors upon the Great Barrier Reef. One of these behaviors includes that of limiting their grazing distances from a patch reef refuge to a certain maximum distance in order to avoid predators. This is defined as a ‘foraging radius’ or ‘margin of safety’. This ‘foraging radius’ varies among fish due to many factors- including species, morphology, ontogenesis, habitat complexity, and importantly: speed. Quicker fish can outswim predators to safety more efficiently than slower fish, and can therefore afford to travel farther distances to forage. Speed varies among fish for a number of reasons, including fish size and shape. In this study, we looked at how fish length affects its foraging radius within a patch reef ecosystem. We found that there was a positive correlation between length and foraging radius, but that this relationship was highly variable among species. The positive relationship was the strongest within the Damselfish family (Pomacentridae), and was also strong within all site-fidelic reef fish species. Overall, a fish’s body shape and maneuverability may contribute more to their foraging radii rather than just their sizes, though many confounding variables also likely impact this relationship. Further research should focus on investigating the effects of these additional factors in order to better understand and protect coral reef ecological dynamics in the face of ongoing reef bleaching caused by a warming climate and ocean acidification.

Recommended Citation

Brawand, Kilia, "Impacts of Reef Fish Length on Foraging Radius: Exploring Behavioral Patterns Within a Patch Reef Ecosystem" (2025). Undergraduate Honors Capstone Projects. 1008.
https://digitalcommons.usu.edu/honors/1008