Habitat preferences and movement patterns of bottlenose dolphins at various spatial and temporal scales

Simple item page
dc.check.embargoformatApply the embargo to the e-thesis on CORA (If you have submitted an e-thesis and want to embargo it on CORA)en
dc.check.entireThesisEntire Thesis Restricted
dc.check.opt-outNot applicableen
dc.check.reasonThis thesis is due for publication or the author is actively seeking to publish this materialen
dc.contributor.advisorRogan, Emeren
dc.contributor.advisorIngram, Simon N.en
dc.contributor.authorGaragouni, Maria
dc.contributor.funderBodossaki Foundationen
dc.date.accessioned2019-09-25T12:02:39Z
dc.date.issued2019
dc.date.submitted2019
dc.description.abstractQuantifying marine mammal abundance, site occupancy, and habitat use patterns is fundamental for the correct design and implementation of conservation and management schemes. Bottlenose dolphins in Irish waters form at least three distinct populations, two coastal and one pelagic, each ranging in different areas over unequal scales. While the abundance of all three has been estimated and core areas of use have been previously identified for the coastal populations, their habitat preferences have not yet been investigated sufficiently. In this thesis, generalised additive models were used to describe the habitat use of each population in relation to a suite of static and dynamic environmental parameters, over a range of temporal scales. Mixed models and generalised estimating equations were implemented to account for spatial and temporal autocorrelation when necessary. The habitat use of the pelagic population was modelled using two seasons (Summer and Winter) of aerial survey data of the greater part of the Irish EEZ and the models’ predictive capacity was tested on observations from two separate seasons. The interaction of environmental covariates with a habitat classifier was also tested to elucidate dolphin habitat use changes depending on whether they are in shelf, slope, or abyssal waters. The site occupancy of the coastal mobile population was modelled using five years of passive acoustic monitoring (C-POD) data from two locations on the west coast at an hourly, daily, and monthly scale. The second coastal population is resident in the outer Shannon estuary Special Area of Conservation and its abundance has been sporadically monitored for nearly two decades using boat-based photo-identification surveys. Encounter data from these surveys were used to model habitat use by incorporating a two-dimensional geographic coordinate term and an interaction with tidal phases. Given the irregular frequency of standardised surveys, I also assessed the potential of using a dolphin-watching boat operating in the same area as an alternative platform from which to derive a robust abundance estimate, using mark-recapture techniques. Different environmental covariates proved significant at each spatial scale, with dolphins showing season-, habitat-, and site-specific responses to each parameter. A higher probability of dolphin presence was predicted over the continental shelf and slope in the winter and in two primary areas in the summer, the southwest coast and the Porcupine Basin. Sea surface temperature and primary productivity were significant predictors of dolphin presence for both the pelagic and mobile coastal population, but not for the resident coastal population. Tidal level had a significant effect on dolphin detection in the coastal mobile population, with the likelihood of detections increasing at higher water levels. Tidal phase was also a significant predictor of dolphin presence for the resident population, with higher probabilities being predicted closer to a bottleneck feature during ebb tides. The abundance estimate generated from the dolphin-watching boat observations compared favourably to an estimate generated from a standardised survey the previous year. This indicates that, in years when standardised surveys do not take place, the dolphin-watching boat may provide a suitable interim platform for more frequent and efficient monitoring of this population. The results presented here highlight the importance of investigating habitat use at different spatial and temporal scales, provide valuable insights regarding areas used at different times by bottlenose dolphins, and form a baseline upon which to build further, more targeted investigations of the habitat preferences, demographic parameters, and abundance of each population, ultimately advancing our efforts at conservation and facilitating marine spatial planning.en
dc.description.statusNot peer revieweden
dc.description.versionAccepted Version
dc.format.mimetypeapplication/pdfen
dc.identifier.citationGaragouni, M. 2019. Habitat preferences and movement patterns of bottlenose dolphins at various spatial and temporal scales. PhD Thesis, University College Cork.en
dc.identifier.endpage173en
dc.identifier.urihttps://hdl.handle.net/10468/8618
dc.language.isoenen
dc.publisherUniversity College Corken
dc.relation.projectBodossaki Foundation (Scholarship for Postgraduate Studies Abroad)en
dc.rights© 2019, Maria Garagouni.en
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/3.0/en
dc.subjectBottlenose dolphinsen
dc.subjectTursiops truncatusen
dc.subjectHabitat useen
dc.subjectHabitat modelsen
dc.subjectAbundanceen
dc.subjectMark-recaptureen
dc.subjectPhoto-identificationen
dc.subjectIrish EEZen
dc.subjectShannon Estuaryen
dc.subjectPlatform of opportunityen
dc.subjectPassive acoustic monitoringen
dc.subjectSite occupancyen
dc.subjectGeneralised additive modelsen
dc.thesis.opt-outfalse
dc.titleHabitat preferences and movement patterns of bottlenose dolphins at various spatial and temporal scalesen
dc.typeDoctoral thesisen
dc.type.qualificationlevelDoctoralen
dc.type.qualificationnamePhDen
ucc.workflow.supervisore.rogan@ucc.ie
Files
Original bundle
Now showing 1 - 2 of 2
Thumbnail Image
Name:
Garagouni_PhD Thesis_UCC.pdf
Size:
4.98 MB
Format:
Adobe Portable Document Format
Description:
Full Text E-thesis
Download
Thumbnail Image
Name:
Garagouni_abstract.docx
Size:
14.26 KB
Format:
Microsoft Word XML
Description:
Abstract
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
5.62 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Doctoral Theses
Biological, Earth and Environmental Sciences - Doctoral Theses
College of Science, Engineering and Food Science - Doctoral Theses