Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability
The North Atlantic Oscillation (NAO) is a dominant climatic driver that influences hydrographic and ecological parameters at multiple spatial scales and several trophic levels. To date, linkages between NAO variability and dolphin strandings on a regional scale have not been investigated. Stranding...
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ftunivrhodeislan:oai:digitalcommons.uri.edu:dissertations-3371 2023-05-15T17:31:23+02:00 Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability Harry, Charles Thomas 2015-01-01T08:00:00Z https://digitalcommons.uri.edu/dissertations/AAI1586302 ENG eng DigitalCommons@URI https://digitalcommons.uri.edu/dissertations/AAI1586302 Dissertations and Master's Theses (Campus Access) Ecology|Biological oceanography|Zoology text 2015 ftunivrhodeislan 2021-06-29T19:28:44Z The North Atlantic Oscillation (NAO) is a dominant climatic driver that influences hydrographic and ecological parameters at multiple spatial scales and several trophic levels. To date, linkages between NAO variability and dolphin strandings on a regional scale have not been investigated. Stranding records of short-beaked common dolphins (Delphinus delphis) and Atlantic white-sided dolphins (Lagenorhynchus acutus) during 1990-2014 between Maine and New York were correlated against the winter NAO index at several time lags in order to explore the link between stranding variability and NAO. The stranding frequencies of the two species were positively correlated to one another. When analyzed against the winter NAO index, the stranding time-series for both species yielded statistically significant inverse correlations at time lags of one and/or two years. Dolphin strandings were lower during the two years after winters when the NAO was positive and were higher during the two years after a negative NAO. Linear regression modeling confirmed a significant relationship between strandings and winter NAO at both 1- and 2-year lags for common dolphins, but not for white-sided dolphins. The hypothesized mechanism underlying the relationship is that NAO-linked hydrographic changes during winter in outer shelf and slope waters affect the abundance and/or availability of prey, leading to changes in the inshore-offshore distribution patterns of the dolphins. Increased occurrence and foraging closer to shore increases the dolphin's susceptibility to stranding caused by other localized or short-term factors. This study represents the first attempt at linking NAO variability to dolphin mortality within New England waters. Text North Atlantic North Atlantic oscillation University of Rhode Island: DigitalCommons@URI |
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University of Rhode Island: DigitalCommons@URI |
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English |
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Ecology|Biological oceanography|Zoology |
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Ecology|Biological oceanography|Zoology Harry, Charles Thomas Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability |
topic_facet |
Ecology|Biological oceanography|Zoology |
description |
The North Atlantic Oscillation (NAO) is a dominant climatic driver that influences hydrographic and ecological parameters at multiple spatial scales and several trophic levels. To date, linkages between NAO variability and dolphin strandings on a regional scale have not been investigated. Stranding records of short-beaked common dolphins (Delphinus delphis) and Atlantic white-sided dolphins (Lagenorhynchus acutus) during 1990-2014 between Maine and New York were correlated against the winter NAO index at several time lags in order to explore the link between stranding variability and NAO. The stranding frequencies of the two species were positively correlated to one another. When analyzed against the winter NAO index, the stranding time-series for both species yielded statistically significant inverse correlations at time lags of one and/or two years. Dolphin strandings were lower during the two years after winters when the NAO was positive and were higher during the two years after a negative NAO. Linear regression modeling confirmed a significant relationship between strandings and winter NAO at both 1- and 2-year lags for common dolphins, but not for white-sided dolphins. The hypothesized mechanism underlying the relationship is that NAO-linked hydrographic changes during winter in outer shelf and slope waters affect the abundance and/or availability of prey, leading to changes in the inshore-offshore distribution patterns of the dolphins. Increased occurrence and foraging closer to shore increases the dolphin's susceptibility to stranding caused by other localized or short-term factors. This study represents the first attempt at linking NAO variability to dolphin mortality within New England waters. |
format |
Text |
author |
Harry, Charles Thomas |
author_facet |
Harry, Charles Thomas |
author_sort |
Harry, Charles Thomas |
title |
Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability |
title_short |
Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability |
title_full |
Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability |
title_fullStr |
Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability |
title_full_unstemmed |
Linkages between New England dolphin stranding frequency and north Atlantic oscillation variability |
title_sort |
linkages between new england dolphin stranding frequency and north atlantic oscillation variability |
publisher |
DigitalCommons@URI |
publishDate |
2015 |
url |
https://digitalcommons.uri.edu/dissertations/AAI1586302 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Dissertations and Master's Theses (Campus Access) |
op_relation |
https://digitalcommons.uri.edu/dissertations/AAI1586302 |
_version_ |
1766128903757234176 |