Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic
The size and trend of a population is fundamental to the assessment of its conservation status, yet cetacean abundance data are often biased and lack statistical power to detect trends. As a result, the conservation status of many species is unknown and the population-level effects of conservation p...
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University of St Andrews
2015
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ftstandrewserep:oai:research-repository.st-andrews.ac.uk:10023/6337 2023-07-02T03:32:30+02:00 Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic Jewell, Rebecca Thomas, Len Tyack, Peter L. 318 2015-03-26T10:04:53Z application/pdf http://hdl.handle.net/10023/6337 en eng University of St Andrews The University of St Andrews School of Biology http://hdl.handle.net/10023/6337 Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ Electronic copy restricted until 24th April 2016 Thesis restricted in accordance with University regulations Cetacean Pilot whale Population trend Stranding North Atlantic Anthropogenic sound Diving behaviour Availability bias Cetacea Globicephala melaena Population trends Whales--Stranding Thesis Doctoral PhD Doctor of Philosophy 2015 ftstandrewserep 2023-06-13T18:27:12Z The size and trend of a population is fundamental to the assessment of its conservation status, yet cetacean abundance data are often biased and lack statistical power to detect trends. As a result, the conservation status of many species is unknown and the population-level effects of conservation pressures such as anthropogenic sound cannot be quantified. Failing to account for cetaceans that are unavailable for detection at the surface during abundance surveys will negatively bias estimates of abundance. Analysis of time-depth data revealed that pilot whale dive and surface interval durations, and availability for detection, varied with time of day, but this bias was accurately estimated using the mean dive and surface interval durations. A global analysis of cetacean density estimates compiled from multiple line-transect surveys incorporated covariates describing availability bias, and other sources of variability, to facilitate the detection of underlying temporal trends. Decadal global trends in cetacean density were detected for four species, while significant yearly ocean-scale trends were detected for six families. Exploratory analysis of data compiled from line-transect surveys found some evidence that trends in the density of minke whales and sperm whales in the northeast Atlantic varied between areas with and without seismic survey effort. However, there were insufficient data to clearly identify chronic exposure to anthropogenic sound from seismic surveys as a driver of population change. Analysis of strandings data from the UK and Ireland identified some evidence that harbour porpoise and sperm whale stranding rates were related to seismic survey effort and wind farm construction, but the results were not conclusive. Large-scale cetacean surveys provide valuable information on the density and spatial and temporal distribution of cetaceans that is vital for monitoring populations, but these surveys cannot replace dedicated studies of the population-level effects of sound on cetaceans. Doctoral or Postdoctoral Thesis Harbour porpoise North Atlantic Northeast Atlantic Sperm whale University of St Andrews: Digital Research Repository |
institution |
Open Polar |
collection |
University of St Andrews: Digital Research Repository |
op_collection_id |
ftstandrewserep |
language |
English |
topic |
Cetacean Pilot whale Population trend Stranding North Atlantic Anthropogenic sound Diving behaviour Availability bias Cetacea Globicephala melaena Population trends Whales--Stranding |
spellingShingle |
Cetacean Pilot whale Population trend Stranding North Atlantic Anthropogenic sound Diving behaviour Availability bias Cetacea Globicephala melaena Population trends Whales--Stranding Jewell, Rebecca Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic |
topic_facet |
Cetacean Pilot whale Population trend Stranding North Atlantic Anthropogenic sound Diving behaviour Availability bias Cetacea Globicephala melaena Population trends Whales--Stranding |
description |
The size and trend of a population is fundamental to the assessment of its conservation status, yet cetacean abundance data are often biased and lack statistical power to detect trends. As a result, the conservation status of many species is unknown and the population-level effects of conservation pressures such as anthropogenic sound cannot be quantified. Failing to account for cetaceans that are unavailable for detection at the surface during abundance surveys will negatively bias estimates of abundance. Analysis of time-depth data revealed that pilot whale dive and surface interval durations, and availability for detection, varied with time of day, but this bias was accurately estimated using the mean dive and surface interval durations. A global analysis of cetacean density estimates compiled from multiple line-transect surveys incorporated covariates describing availability bias, and other sources of variability, to facilitate the detection of underlying temporal trends. Decadal global trends in cetacean density were detected for four species, while significant yearly ocean-scale trends were detected for six families. Exploratory analysis of data compiled from line-transect surveys found some evidence that trends in the density of minke whales and sperm whales in the northeast Atlantic varied between areas with and without seismic survey effort. However, there were insufficient data to clearly identify chronic exposure to anthropogenic sound from seismic surveys as a driver of population change. Analysis of strandings data from the UK and Ireland identified some evidence that harbour porpoise and sperm whale stranding rates were related to seismic survey effort and wind farm construction, but the results were not conclusive. Large-scale cetacean surveys provide valuable information on the density and spatial and temporal distribution of cetaceans that is vital for monitoring populations, but these surveys cannot replace dedicated studies of the population-level effects of sound on cetaceans. |
author2 |
Thomas, Len Tyack, Peter L. |
format |
Doctoral or Postdoctoral Thesis |
author |
Jewell, Rebecca |
author_facet |
Jewell, Rebecca |
author_sort |
Jewell, Rebecca |
title |
Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic |
title_short |
Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic |
title_full |
Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic |
title_fullStr |
Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic |
title_full_unstemmed |
Investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast Atlantic |
title_sort |
investigating the surfacing and diving behaviour and availability of long-finned pilot whales and quantifying the effects of anthropogenic sound on density and strandings of cetaceans in the northeast atlantic |
publisher |
University of St Andrews |
publishDate |
2015 |
url |
http://hdl.handle.net/10023/6337 |
op_coverage |
318 |
genre |
Harbour porpoise North Atlantic Northeast Atlantic Sperm whale |
genre_facet |
Harbour porpoise North Atlantic Northeast Atlantic Sperm whale |
op_relation |
http://hdl.handle.net/10023/6337 |
op_rights |
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ Electronic copy restricted until 24th April 2016 Thesis restricted in accordance with University regulations |
_version_ |
1770272085900263424 |