Abstract

The hawksbill (Eretmochelys imbricata) sea turtle has been classified as critically endangered. Reductions in populations call for protective strategies, one being the implementation of protected areas. However, as a highly migratory species, preservation and restoration is difficult, as protection is required in nesting, foraging, and breeding regions. To establish adequate protected areas to aid hawksbill survival, a clear understanding of movement patterns between protected and unprotected regions is required. A foraging aggregation of juvenile hawksbills resides off the coast of Roatán, Honduras within the Sandy Bay West End Marine Reserve. The reserve is a protected area, but also spans the coast of a popular tourist region. As tourism in the area continues to increase, the use of boats continues to rise. Alteration of marine organism behavior, injury and mortality are common results of increased boating pressure, but boating activities in the reserve is increasing without assessment or the implementation of additional regulations. I set out to estimate international connections between this protected aggregation and international nesting rookeries, to assess the suitability of the reserve as a recruitment zone, and to further assess the effect of boating pressure on hawksbill distribution and behavior. Using mitochondrial DNA haplotypes, I evaluated the genetic structure of this foraging aggregation and further estimated natal origins through mixed stock analysis. I assessed the suitability of the reserve using species distribution modeling in MaxEnt and used resource, disturbance, and benthic environmental values as predictor variables. Using a series of in-water behavioral observations, I assessed the effect of boat traffic on hawksbill distribution and behavior. Haplotype analysis suggested the presence of unique haplotypes not currently associated with known nesting rookeries. Mixed stock analyses suggest that juveniles in the reserve originated from rookeries in Colombia, Puerto Rico, and Costa Rica. MaxEnt outputs suggested that the reserve is moderately to highly suitable for hawksbill inhabitance, with resource environmental variables having the greatest influence on species distribution. Although hawksbills remain at risk of boat strikes, increased boating pressure did not significantly affect in-water behavior. Since the reserve is an important local foraging area for juvenile hawksbills, measures to maintain and increase suitability should be implemented.

LLU Discipline

Biology

Department

Biology

School

School of Medicine

First Advisor

Stephen G. Dunbar

Second Advisor

Ronald L. Carter

Third Advisor

Noemi Duran

Fourth Advisor

William K. Hayes

Fifth Advisor

Suzanne Phillips

Sixth Advisor

Kenneth Wright

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

2020

Date (Title Page)

5-2020

Language

English

Library of Congress/MESH Subject Headings

Marine ecology; Hawksbill turtle -- Caribbean

Type

Dissertation

Page Count

xv, 162 p.

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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