Date of Award
2025
Degree Type
Dissertation
Degree Name
Doctor of Philosophy in Oceanography
Specialization
Biological Oceanography
Department
Oceanography
First Advisor
Kelton McMahon
Abstract
Coral reef socio-ecological systems (SESs) characterize the interconnected relationships between coral reef ecosystems and reef-dependent communities. One such SES exists in Ulithi Atoll, Federated States of Micronesia, where Ulithians fish, steward, and govern their reefs through customary marine tenure, traditional ecological knowledge, and cultural taboos. In recent decades, rapid modernization in Ulithi has introduced new fishing technologies, transformed fishing practices, and ultimately reshaped the functioning of Ulithi’s traditional SES. One significant change was the introduction of spearfishing during the mid-20th century, which is more selective and individualistic compared to other community-centric fishing methods that have existed for generations. This dissertation uses ethnographic, fisheries, and isotopic data to investigate the introduction of spearfishing to Ulithi and its impact on the SES. In the first chapter, I document the history of Ulithian spearfishing and employ a political ecology framework to trace the arrival of Western spearguns. Here, I argue that spearfishing history is defined by both Western influences and local innovation, and that Western spearguns, specifically, are a product of migration and reciprocity. In the second chapter, I analyze fisheries catch data from Ulithi to compare spearfishing catch metrics and composition to other fishing methods and examine potential socio-ecological outcomes. I found that spearfishing required less effort, landed greater biomass, and was used to preferentially land larger individuals and herbivorous fishes. Evidence suggests a spearfishing-mediated “fishing down the food web” effect in Ulithi; however, increased catch biomass after a category five typhoon also indicates spearfishing to be important for fish provision during times of emergency. In the third chapter, I explore why fishers spearfish by conducting focus group interviews centered on spearfishing perceptions and practices of Ulithian communities. Participants generally preferred spearfishing and responses portrayed spearfishing as a complex, dynamic system upholding multiple sociocultural provisions beyond subsistence. Additionally, spearfishing appears to have undergone cultural integration and “recreationalization”, where the recreational attributes of spearfishing have increased in perceived importance. In the fourth and final chapter, I use compound-specific isotope analysis of amino acids to resolve herbivory among three heavily targeted nominally herbivorous fishes: Chlorurus spilurus, Ctenochaetus striatus, and Naso lituratus. Essential amino acid d13C fingerprinting and three additional d15N metrics (d15NLys, Dd15NGlu-Lys, and SV) indicated N. lituratus to be the most classically herbivorous species. Furthermore, our isotopic data suggest that the nutritional ecology of herbivorous fishes are distinct from their functional roles. Together, my interdisciplinary dissertation reveals a suite of complexities surrounding Ulithian spearfishing, including its mix of Western and local influences, its dichotomous socio-ecological impacts, its sociocultural importance beyond subsistence, and the decoupling of nutrition and function in target species. These findings not only provide valuable insights for the management of coral reef spearfisheries, but also inform the relationships among humans, fishing technology, and marine environments across other coastal SESs.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Pi, Joshua, "A SOCIO-ECOLOGICAL INVESTIGATION OF ULITHIAN SPEARFISHING" (2025). Open Access Dissertations. Paper 4508.
https://digitalcommons.uri.edu/oa_diss/4508