Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000
Aerial surveys were conducted in 1999 and 2000 to estimate the densities of ringed (Phoca hispida) and bearded (Erignathus barbatus) seals in the eastern Chukchi Sea. Survey lines were focused mainly on the coastal zone within 37 km of the shoreline, with additional lines flown 148–185 km offshore t...
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ftunivnebraskali:oai:digitalcommons.unl.edu:usdeptcommercepub-1153 2023-11-12T04:15:09+01:00 Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000 Bengtson, John L. Hiruki-Raring, Lisa M. Simpkins, Michael A. Boveng, Peter L. 2005-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/usdeptcommercepub/143 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1153/viewcontent/Boveng_PB_2005_Ringed_and_bearded_seal.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/usdeptcommercepub/143 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1153/viewcontent/Boveng_PB_2005_Ringed_and_bearded_seal.pdf Publications, Agencies and Staff of the U.S. Department of Commerce Environmental Sciences text 2005 ftunivnebraskali 2023-10-30T10:43:04Z Aerial surveys were conducted in 1999 and 2000 to estimate the densities of ringed (Phoca hispida) and bearded (Erignathus barbatus) seals in the eastern Chukchi Sea. Survey lines were focused mainly on the coastal zone within 37 km of the shoreline, with additional lines flown 148–185 km offshore to assess how densities of seals changed as a function of distance from shore. Satellite-linked time-depth recorders were attached to ringed seals in both years to evaluate the time spent basking on the ice surface. Haulout patterns indicated that ringed seals transitioned to basking behavior in late May and early June, and that the largest proportion of seals (60–68%) was hauled out between 0830 and 1530 local solar time. Ringed seals were relatively common in nearshore fast ice and pack ice, with lower densities in offshore pack ice. The average density of ringed seals was 1.91 seals km-2 in 1999 (range 0.37– 16.32) and 1.62 seals km-2 in 2000 (range 0.42–19.4), with the highest densities of ringed seals found in coastal waters south of Kivalina and near Kotzebue Sound. The estimated abundance of ringed seals for the entire study area was similar in 1999 (252,488 seals, SE=47,204) and 2000 (208,857 seals, SE=25,502). Bearded seals were generally more common in offshore pack ice, with the exception of high bearded seal numbers observed near the shore south of Kivalina. Bearded seal densities were not adjusted for haulout behavior, and therefore, abundance was not estimated. Unadjusted average bearded seal density was 0.07 seals km-2 in 1999 (range 0.011–0.393) and 0.14 seals km-2 in 2000 (range 0.009– 0.652). Levels of primary productivity, benthic biomass, and fast ice distribution may influence the distributions of ringed and bearded seals in the Chukchi Sea. Information on movement and haulout behavior of ringed and bearded seals would be very useful for designing future surveys. Text bearded seal Chukchi Chukchi Sea Erignathus barbatus Phoca hispida University of Nebraska-Lincoln: DigitalCommons@UNL Chukchi Sea |
institution |
Open Polar |
collection |
University of Nebraska-Lincoln: DigitalCommons@UNL |
op_collection_id |
ftunivnebraskali |
language |
unknown |
topic |
Environmental Sciences |
spellingShingle |
Environmental Sciences Bengtson, John L. Hiruki-Raring, Lisa M. Simpkins, Michael A. Boveng, Peter L. Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000 |
topic_facet |
Environmental Sciences |
description |
Aerial surveys were conducted in 1999 and 2000 to estimate the densities of ringed (Phoca hispida) and bearded (Erignathus barbatus) seals in the eastern Chukchi Sea. Survey lines were focused mainly on the coastal zone within 37 km of the shoreline, with additional lines flown 148–185 km offshore to assess how densities of seals changed as a function of distance from shore. Satellite-linked time-depth recorders were attached to ringed seals in both years to evaluate the time spent basking on the ice surface. Haulout patterns indicated that ringed seals transitioned to basking behavior in late May and early June, and that the largest proportion of seals (60–68%) was hauled out between 0830 and 1530 local solar time. Ringed seals were relatively common in nearshore fast ice and pack ice, with lower densities in offshore pack ice. The average density of ringed seals was 1.91 seals km-2 in 1999 (range 0.37– 16.32) and 1.62 seals km-2 in 2000 (range 0.42–19.4), with the highest densities of ringed seals found in coastal waters south of Kivalina and near Kotzebue Sound. The estimated abundance of ringed seals for the entire study area was similar in 1999 (252,488 seals, SE=47,204) and 2000 (208,857 seals, SE=25,502). Bearded seals were generally more common in offshore pack ice, with the exception of high bearded seal numbers observed near the shore south of Kivalina. Bearded seal densities were not adjusted for haulout behavior, and therefore, abundance was not estimated. Unadjusted average bearded seal density was 0.07 seals km-2 in 1999 (range 0.011–0.393) and 0.14 seals km-2 in 2000 (range 0.009– 0.652). Levels of primary productivity, benthic biomass, and fast ice distribution may influence the distributions of ringed and bearded seals in the Chukchi Sea. Information on movement and haulout behavior of ringed and bearded seals would be very useful for designing future surveys. |
format |
Text |
author |
Bengtson, John L. Hiruki-Raring, Lisa M. Simpkins, Michael A. Boveng, Peter L. |
author_facet |
Bengtson, John L. Hiruki-Raring, Lisa M. Simpkins, Michael A. Boveng, Peter L. |
author_sort |
Bengtson, John L. |
title |
Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000 |
title_short |
Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000 |
title_full |
Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000 |
title_fullStr |
Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000 |
title_full_unstemmed |
Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000 |
title_sort |
ringed and bearded seal densities in the eastern chukchi sea, 1999–2000 |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2005 |
url |
https://digitalcommons.unl.edu/usdeptcommercepub/143 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1153/viewcontent/Boveng_PB_2005_Ringed_and_bearded_seal.pdf |
geographic |
Chukchi Sea |
geographic_facet |
Chukchi Sea |
genre |
bearded seal Chukchi Chukchi Sea Erignathus barbatus Phoca hispida |
genre_facet |
bearded seal Chukchi Chukchi Sea Erignathus barbatus Phoca hispida |
op_source |
Publications, Agencies and Staff of the U.S. Department of Commerce |
op_relation |
https://digitalcommons.unl.edu/usdeptcommercepub/143 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1153/viewcontent/Boveng_PB_2005_Ringed_and_bearded_seal.pdf |
_version_ |
1782332558302773248 |