Uncovering the Long-Term Dynamics of Reef Manta Ray (Mobula alfredi) Aggregations in Kona, Hawai‘i Using Community-Sourced Data

Simple item page
dc.contributor.advisorHolland, Kim
dc.contributor.authorNevels, Corey Rae
dc.contributor.departmentMarine Biology
dc.date.accessioned2025-02-20T22:36:52Z
dc.date.available2025-02-20T22:36:52Z
dc.date.issued2024
dc.description.degreeM.S.
dc.identifier.urihttps://hdl.handle.net/10125/110217
dc.subjectBiology
dc.subjectWildlife management
dc.subjectEcology
dc.subjectaggregation dynamics
dc.subjectcitizen science
dc.subjectconservation
dc.subjectmanta rays
dc.subjectresidency
dc.subjecttrends
dc.titleUncovering the Long-Term Dynamics of Reef Manta Ray (Mobula alfredi) Aggregations in Kona, Hawai‘i Using Community-Sourced Data
dc.typeThesis
dcterms.abstractReef manta rays (Mobula alfredi) face conservation challenges due to global population declines and their susceptibility to anthropogenic pressures, particularly in tourism-driven settings. Fine-scale, site-specific studies are essential for understanding population characteristics and informing effective conservation measures. This study leverages citizen science data spanning 13 years (2010-2022) to elucidate the dynamics, residency patterns, and influence of prey availability of manta ray aggregations at two nighttime feeding sites, Garden Eel Cove (GEC) and Keauhou (KH), along the Kona coast of Hawai‘i Island. With over 23,000 recorded sightings of 167 unique individuals, the results reveal both similarities and site-specific distinctions between the two locations. For example, GEC consistently supports larger aggregations than KH, underscoring its role as a reliable feeding area. Both sites exhibited an overall balanced 1:1 sex ratio; however, while GEC showed similar visitation patterns for both sexes, KH was predominately frequented by females, suggesting that this area may serve other sex-specific ecological functions beyond nighttime feeding. The results also support previous indications that males are more mobile than females. Residency and movement patterns were analyzed using a modified maximum likelihood approach, confirming high site fidelity among females at KH and highlighting a degree of connectivity between the two sites. Fluctuations in seasonal and annual trends in aggregation size closely aligned with zooplankton density, emphasizing prey availability as a primary driver of manta presence and aggregation patterns. The relative stability of aggregations at both sites, despite increased tourism, suggests that current activity levels have not negatively impacted the viability of the local manta ray population and that they exhibit adaptable foraging strategies. These findings underscore the ecological significance of GEC and KH for Kona’s manta population and illustrate the potential of community-sourced data to capture long-term ecological patterns, providing a foundation for future research to inform conservation strategies tailored to these key aggregation sites.
dcterms.extent63 pages
dcterms.languageen
dcterms.publisherUniversity of Hawai'i at Manoa
dcterms.rightsAll UHM dissertations and theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
dcterms.typeText
local.identifier.alturihttp://dissertations.umi.com/hawii:12399

Files

Original bundle

Now showing 1 - 1 of 1
Thumbnail Image
Name:
Nevels_hawii_0085O_12399.pdf
Size:
2.29 MB
Format:
Adobe Portable Document Format
Download

Collections

M.S. - Marine Biology