Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords
Tidewater glaciers calve icebergs into the marine environment which serve as pupping, molting, and resting habitat for some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world. Although they are naturally dynamic, advancing and retreating in response to local...
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| Format: | Article |
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Frontiers Media S.A.
2021-05-01
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| Series: | Frontiers in Marine Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmars.2021.634541/full |
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| author | Jamie N. Womble Perry J. Williams Robert W. McNabb Robert W. McNabb Anupma Prakash Rudiger Gens Rudiger Gens Benjamin S. Sedinger Cheyenne R. Acevedo |
| author_facet | Jamie N. Womble Perry J. Williams Robert W. McNabb Robert W. McNabb Anupma Prakash Rudiger Gens Rudiger Gens Benjamin S. Sedinger Cheyenne R. Acevedo |
| author_sort | Jamie N. Womble |
| collection | DOAJ |
| description | Tidewater glaciers calve icebergs into the marine environment which serve as pupping, molting, and resting habitat for some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world. Although they are naturally dynamic, advancing and retreating in response to local climatic and fjord conditions, most tidewater glaciers around the world are thinning and retreating. Climate change models predict continued loss of land-based ice with unknown impacts to organisms such as harbor seals that rely on glacier ice as habitat for critical life history events. To understand the impacts of changing ice availability on harbor seals, we quantified seasonal and annual changes in ice habitat in Johns Hopkins Inlet, a tidewater glacier fjord in Glacier Bay National Park in southeastern Alaska. We conducted systematic aerial photographic surveys (n = 55) of seals and ice during the pupping (June; n = 30) and molting (August; n = 25) periods from 2007 to 2014. Object-based image analysis was used to quantify the availability and spatial distribution of floating ice in the fjord. Multivariate spatial models were developed for jointly modeling stage-structured seal location data and ice habitat. Across all years, there was consistently more ice in the fjord during the pupping season in June than during the molting season in August, which was likely driven by seasonal variation in physical processes that influence the calving dynamics of tidewater glaciers. Non-pup harbor seals and ice were correlated during the pupping season, but this correlation was reduced during the molting season suggesting that harbor seals may respond to changes in habitat differently depending upon trade-offs associated with life history events, such as pupping and molting, and energetic costs and constraints associated with the events. |
| first_indexed | 2024-12-19T06:19:16Z |
| format | Article |
| id | doaj.art-645ec5d1b8f342af99559a39711005fc |
| institution | Directory Open Access Journal |
| issn | 2296-7745 |
| language | English |
| last_indexed | 2024-12-19T06:19:16Z |
| publishDate | 2021-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Marine Science |
| spelling | doaj.art-645ec5d1b8f342af99559a39711005fc2022-12-21T20:32:47ZengFrontiers Media S.A.Frontiers in Marine Science2296-77452021-05-01810.3389/fmars.2021.634541634541Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier FjordsJamie N. Womble0Perry J. Williams1Robert W. McNabb2Robert W. McNabb3Anupma Prakash4Rudiger Gens5Rudiger Gens6Benjamin S. Sedinger7Cheyenne R. Acevedo8Glacier Bay National Park and Preserve and Southeast Alaska Network, National Park Service, Juneau, AK, United StatesDepartment of Natural Resources and Environmental Science, University of Nevada-Reno, Reno, NV, United StatesGeophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United StatesSchool of Geography and Environmental Sciences, Ulster University, Coleraine, United KingdomGeophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United StatesGeophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United StatesAlaska Satellite Facility, Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United StatesDepartment of Natural Resources and Environmental Science, University of Nevada-Reno, Reno, NV, United StatesDepartment of Natural Resources and Environmental Science, University of Nevada-Reno, Reno, NV, United StatesTidewater glaciers calve icebergs into the marine environment which serve as pupping, molting, and resting habitat for some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world. Although they are naturally dynamic, advancing and retreating in response to local climatic and fjord conditions, most tidewater glaciers around the world are thinning and retreating. Climate change models predict continued loss of land-based ice with unknown impacts to organisms such as harbor seals that rely on glacier ice as habitat for critical life history events. To understand the impacts of changing ice availability on harbor seals, we quantified seasonal and annual changes in ice habitat in Johns Hopkins Inlet, a tidewater glacier fjord in Glacier Bay National Park in southeastern Alaska. We conducted systematic aerial photographic surveys (n = 55) of seals and ice during the pupping (June; n = 30) and molting (August; n = 25) periods from 2007 to 2014. Object-based image analysis was used to quantify the availability and spatial distribution of floating ice in the fjord. Multivariate spatial models were developed for jointly modeling stage-structured seal location data and ice habitat. Across all years, there was consistently more ice in the fjord during the pupping season in June than during the molting season in August, which was likely driven by seasonal variation in physical processes that influence the calving dynamics of tidewater glaciers. Non-pup harbor seals and ice were correlated during the pupping season, but this correlation was reduced during the molting season suggesting that harbor seals may respond to changes in habitat differently depending upon trade-offs associated with life history events, such as pupping and molting, and energetic costs and constraints associated with the events.https://www.frontiersin.org/articles/10.3389/fmars.2021.634541/fullfjordhabitatharbor sealicePhoca vitulina richardiitidewater glacier |
| spellingShingle | Jamie N. Womble Perry J. Williams Robert W. McNabb Robert W. McNabb Anupma Prakash Rudiger Gens Rudiger Gens Benjamin S. Sedinger Cheyenne R. Acevedo Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords Frontiers in Marine Science fjord habitat harbor seal ice Phoca vitulina richardii tidewater glacier |
| title | Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords |
| title_full | Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords |
| title_fullStr | Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords |
| title_full_unstemmed | Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords |
| title_short | Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords |
| title_sort | harbor seals as sentinels of ice dynamics in tidewater glacier fjords |
| topic | fjord habitat harbor seal ice Phoca vitulina richardii tidewater glacier |
| url | https://www.frontiersin.org/articles/10.3389/fmars.2021.634541/full |
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