Stable Isotope Analysis of Dermis and the Foraging Behavior of Whale Sharks at Ningaloo Reef, Western Australia

Whale sharks at Ningaloo Reef, Western Australia, primarily rely on pelagic primary and secondary productivity over approximately three years, as revealed by stable isotope analysis of their dermis. This study provides new insights into the foraging behavior and diet of whale sharks, a highly migratory species, by comparing isotopic values (δ13C and δ15N) from whale shark dermis with those of potential prey like krill, zooplankton, and polychaetes. The consistency in δ13C values suggests regional foraging ranges across Ningaloo Reef and the western Australian coast, while variability in δ15N values indicates diverse foraging patterns among individuals. Additionally, evidence of 15N enrichment with increasing size in both male and female whale sharks hints at ontogenetic shifts in trophic level or feeding grounds. This research underscores the importance of understanding temporal and spatial foraging dynamics for effective conservation management of this elusive species.

Marcus, L., Virtue, P., Nichols, P. D., Ferreira, L. C., Pethybridge, H., & Meekan, M. G. (2019). Stable Isotope Analysis of Dermis and the Foraging Behavior of Whale Sharks at Ningaloo Reef, Western Australia. Frontiers in Marine Science, 6. https://doi.org/10.3389/fmars.2019.00546