Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior

Ph.D. University of Hawaii at Manoa 2016. Includes bibliographical references. Patchiness of prey can influence the behavior of a predator, as predicted by the optimal foraging theory which states that an animal will maximize the energy gain while minimizing energy loss. While this relationship has...

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Main Author: Copeland, Adrienne
Format: Thesis
Language:English
Published: [Honolulu] : [University of Hawaii at Manoa], [August 2016] 2016
Subjects:
Online Access:http://hdl.handle.net/10125/51482
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spelling ftunivhawaiimano:oai:scholarspace.manoa.hawaii.edu:10125/51482 2023-07-30T04:07:17+02:00 Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior Copeland, Adrienne 2016-08 application/pdf http://hdl.handle.net/10125/51482 eng eng [Honolulu] : [University of Hawaii at Manoa], [August 2016] Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Zoology http://hdl.handle.net/10125/51482 Thesis Text 2016 ftunivhawaiimano 2023-07-08T22:27:57Z Ph.D. University of Hawaii at Manoa 2016. Includes bibliographical references. Patchiness of prey can influence the behavior of a predator, as predicted by the optimal foraging theory which states that an animal will maximize the energy gain while minimizing energy loss. While this relationship has been studied and is relatively well understood in some terrestrial systems, the same is far from true in marine systems. It is as important to investigate this in the marine realm in order to better understand predator distribution and behavior. Micronekton, organisms from 2 – 20 cm, might be a key component in understanding this as it is potentially an essential link in the food web between primary producers and higher trophic levels, including cephalopods which are primary prey items of deep diving odontocetes (toothed whales). My dissertation assesses the spatial and temporal variability of micronekton in the Northwestern Hawaiian Islands (NWHI), the Main Hawaiian Islands’ (MHI) Island of Hawaii, and the Gulf of Mexico (GOM). Additionally it focuses on understanding the relationship between the spatial distribution of micronekton and environmental and geographic factors, and how the spatial and temporal variability of this micronekton relates to deep diving odontocete foraging. I used both an active Simrad EK60 echosounder system to collect water column micronekton backscatter and a passive acoustic system to detect the presence of echolocation clicks from deep diving beaked, sperm, and short-finned pilot whales. My results provide insight into what might be contributing to hotspots of micronekton which formed discrete layers in all locations, a shallow scattering layer (SSL) from the surface to about 200 m and a deep scattering layer (DSL) starting at about 350 m. In both the GOM and the NWHI, the bathymetry and proximity to shore influenced the amount of micronekton backscatter with locations closer to shore and at shallower depths having higher backscatter. We found in all three locations that some species ... Thesis toothed whales ScholarSpace at University of Hawaii at Manoa
institution Open Polar
collection ScholarSpace at University of Hawaii at Manoa
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language English
description Ph.D. University of Hawaii at Manoa 2016. Includes bibliographical references. Patchiness of prey can influence the behavior of a predator, as predicted by the optimal foraging theory which states that an animal will maximize the energy gain while minimizing energy loss. While this relationship has been studied and is relatively well understood in some terrestrial systems, the same is far from true in marine systems. It is as important to investigate this in the marine realm in order to better understand predator distribution and behavior. Micronekton, organisms from 2 – 20 cm, might be a key component in understanding this as it is potentially an essential link in the food web between primary producers and higher trophic levels, including cephalopods which are primary prey items of deep diving odontocetes (toothed whales). My dissertation assesses the spatial and temporal variability of micronekton in the Northwestern Hawaiian Islands (NWHI), the Main Hawaiian Islands’ (MHI) Island of Hawaii, and the Gulf of Mexico (GOM). Additionally it focuses on understanding the relationship between the spatial distribution of micronekton and environmental and geographic factors, and how the spatial and temporal variability of this micronekton relates to deep diving odontocete foraging. I used both an active Simrad EK60 echosounder system to collect water column micronekton backscatter and a passive acoustic system to detect the presence of echolocation clicks from deep diving beaked, sperm, and short-finned pilot whales. My results provide insight into what might be contributing to hotspots of micronekton which formed discrete layers in all locations, a shallow scattering layer (SSL) from the surface to about 200 m and a deep scattering layer (DSL) starting at about 350 m. In both the GOM and the NWHI, the bathymetry and proximity to shore influenced the amount of micronekton backscatter with locations closer to shore and at shallower depths having higher backscatter. We found in all three locations that some species ...
format Thesis
author Copeland, Adrienne
spellingShingle Copeland, Adrienne
Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior
author_facet Copeland, Adrienne
author_sort Copeland, Adrienne
title Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior
title_short Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior
title_full Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior
title_fullStr Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior
title_full_unstemmed Influences of Spatial and Temporal Variability of Sound Scattering Layers on Deep Diving Odontocete Behavior
title_sort influences of spatial and temporal variability of sound scattering layers on deep diving odontocete behavior
publisher [Honolulu] : [University of Hawaii at Manoa], [August 2016]
publishDate 2016
url http://hdl.handle.net/10125/51482
genre toothed whales
genre_facet toothed whales
op_relation Theses for the degree of Doctor of Philosophy (University of Hawaii at Manoa). Zoology
http://hdl.handle.net/10125/51482
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