Characterization of Novel Whale Shark Aggregations at Shib Habil, Saudi Arabia and Mafia Island, Tanzania

Handle URI:
http://hdl.handle.net/10754/336799
Title:
Characterization of Novel Whale Shark Aggregations at Shib Habil, Saudi Arabia and Mafia Island, Tanzania
Authors:
Cochran, Jesse ( 0000-0002-6027-5052 )
Abstract:
Passive acoustic monitoring has been successfully used on many elasmobranch species, but no such study has yet been published for the whale shark (Rhincodon typus). In some ways this is surprising as the known whale shark aggregation sites would seem to be ideal targets for this method. For this dissertation, two acoustic studies were carried out in Saudi Arabia and Tanzania. Each was performed in parallel with visual surveys and the Saudi population was also studied using satellite telemetry. Sighting and acoustic data were compared at both sites, and the results were mixed. The acoustic monitoring largely confirmed the results of visual surveys for the Saudi Arabian sharks, including seasonality, residency and a degree of parity and integration between the sexes that is unique to this site. Satellite tracks of tagged Saudi sharks were used to confirm that some animals migrated away from the aggregation site before returning in subsequent seasons, confirming philopatric behavior in this species. In contrast, the acoustic results in Tanzania demonstrated year-round residency of whale sharks in the area, despite seasonal declines in visually estimated abundance. Seasonal changes in habitat selection render the sharks at this site temporarily cryptic to visual sampling. The differing results are compelling because both the philopatric behavior demonstrated in Saudi Arabia and the cryptic residency of the Tanzanian sharks could explain the seasonal patterns in whale shark abundances reported at other aggregation sites. Despite their differences, both sites in this study can be classified as secondary whale shark nurseries and each may be a vital feeding ground for its respective population.
Advisors:
Berumen, Michael L. ( 0000-0003-2463-2742 )
Committee Member:
Genton, Marc; Jones, Burton ( 0000-0002-9599-1593 ) ; Skomal, Greg
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division
Program:
Marine Science
Issue Date:
Dec-2014
Type:
Dissertation
Additional Links:
http://hdl.handle.net/10754/334559
Appears in Collections:
Marine Science Program; Dissertations; Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.advisorBerumen, Michael L.en
dc.contributor.authorCochran, Jesseen
dc.date.accessioned2014-12-08T11:12:37Z-
dc.date.available2014-12-08T11:12:37Z-
dc.date.issued2014-12en
dc.identifier.urihttp://hdl.handle.net/10754/336799en
dc.description.abstractPassive acoustic monitoring has been successfully used on many elasmobranch species, but no such study has yet been published for the whale shark (Rhincodon typus). In some ways this is surprising as the known whale shark aggregation sites would seem to be ideal targets for this method. For this dissertation, two acoustic studies were carried out in Saudi Arabia and Tanzania. Each was performed in parallel with visual surveys and the Saudi population was also studied using satellite telemetry. Sighting and acoustic data were compared at both sites, and the results were mixed. The acoustic monitoring largely confirmed the results of visual surveys for the Saudi Arabian sharks, including seasonality, residency and a degree of parity and integration between the sexes that is unique to this site. Satellite tracks of tagged Saudi sharks were used to confirm that some animals migrated away from the aggregation site before returning in subsequent seasons, confirming philopatric behavior in this species. In contrast, the acoustic results in Tanzania demonstrated year-round residency of whale sharks in the area, despite seasonal declines in visually estimated abundance. Seasonal changes in habitat selection render the sharks at this site temporarily cryptic to visual sampling. The differing results are compelling because both the philopatric behavior demonstrated in Saudi Arabia and the cryptic residency of the Tanzanian sharks could explain the seasonal patterns in whale shark abundances reported at other aggregation sites. Despite their differences, both sites in this study can be classified as secondary whale shark nurseries and each may be a vital feeding ground for its respective population.en
dc.language.isoenen
dc.relation.urlhttp://hdl.handle.net/10754/334559en
dc.subjectWhale Sharken
dc.subjectAggregationen
dc.subjectTelemetryen
dc.subjectPhoto IDen
dc.titleCharacterization of Novel Whale Shark Aggregations at Shib Habil, Saudi Arabia and Mafia Island, Tanzaniaen
dc.typeDissertationen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
thesis.degree.grantorKing Abdullah University of Science and Technologyen_GB
dc.contributor.committeememberGenton, Marcen
dc.contributor.committeememberJones, Burtonen
dc.contributor.committeememberSkomal, Gregen
thesis.degree.disciplineMarine Scienceen
thesis.degree.nameDoctor of Philosophyen
dc.person.id113369en
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