Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993
Between 1991 and 1993, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during aerial surveys throughout much of the coastal and offshore waters from Bristol Bay in the eastern Bering Sea to Dixon Entrance in Southeast Alaska. Line-transect methodology was used, and only those o...
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ftunivnebraskali:oai:digitalcommons.unl.edu:usdeptcommercepub-1173 2023-11-12T04:15:20+01:00 Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993 Dahlheim, M. York, A. Towell, R. Waite, J. Breiwick, J. 2000-01-01T08:00:00Z application/pdf https://digitalcommons.unl.edu/usdeptcommercepub/173 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1173/viewcontent/Dahlheim_MMS_2000_Harbor_porpoise.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/usdeptcommercepub/173 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1173/viewcontent/Dahlheim_MMS_2000_Harbor_porpoise.pdf Publications, Agencies and Staff of the U.S. Department of Commerce Environmental Sciences text 2000 ftunivnebraskali 2023-10-30T09:43:17Z Between 1991 and 1993, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during aerial surveys throughout much of the coastal and offshore waters from Bristol Bay in the eastern Bering Sea to Dixon Entrance in Southeast Alaska. Line-transect methodology was used, and only those observations made during optimal conditions were analyzed. Survey data indicated densities of 4.48 groups/100 km2, or approximately 3,531 harbor porpoises (95% C.I. 2,206-5,651) in Bristol Bay and 0.54 groups/100 km2, or 136 harbor porpoises (95% C.I. 11-1,645) for Cook Inlet. Efforts off Kodiak Island resulted in densities of 1.85 groups/100 km2, or an abundance estimate of 740 (95% C.I. 259-2,115). Surveys off the south side of the Alaska Peninsula found densities of 2.03 groups/100 km2 and an abundance estimate of 551 (95% C.I. 423-719). Surveys of offshore waters from Prince William Sound to Dixon Entrance yielded densities of 4.02 groups/100 km’ and an abundance estimate of 3,982 (95% C.I. 2,567-6,177). Combining all years and areas yielded an uncorrected density estimate of 3.82 porpoises per 100 km2, resulting in an abundance estimate of 8,940 porpoises (CV = 13.8%) with a 95% confidence interval of 6,746-11,848. Using correction factors from other studies to adjust for animals missed by observers, the total number of Alaska harbor porpoises is probably three times this number. Text Bering Sea Kodiak Phocoena phocoena Alaska University of Nebraska-Lincoln: DigitalCommons@UNL Bering Sea Dixon Entrance ENVELOPE(-132.003,-132.003,54.416,54.416) |
institution |
Open Polar |
collection |
University of Nebraska-Lincoln: DigitalCommons@UNL |
op_collection_id |
ftunivnebraskali |
language |
unknown |
topic |
Environmental Sciences |
spellingShingle |
Environmental Sciences Dahlheim, M. York, A. Towell, R. Waite, J. Breiwick, J. Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993 |
topic_facet |
Environmental Sciences |
description |
Between 1991 and 1993, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during aerial surveys throughout much of the coastal and offshore waters from Bristol Bay in the eastern Bering Sea to Dixon Entrance in Southeast Alaska. Line-transect methodology was used, and only those observations made during optimal conditions were analyzed. Survey data indicated densities of 4.48 groups/100 km2, or approximately 3,531 harbor porpoises (95% C.I. 2,206-5,651) in Bristol Bay and 0.54 groups/100 km2, or 136 harbor porpoises (95% C.I. 11-1,645) for Cook Inlet. Efforts off Kodiak Island resulted in densities of 1.85 groups/100 km2, or an abundance estimate of 740 (95% C.I. 259-2,115). Surveys off the south side of the Alaska Peninsula found densities of 2.03 groups/100 km2 and an abundance estimate of 551 (95% C.I. 423-719). Surveys of offshore waters from Prince William Sound to Dixon Entrance yielded densities of 4.02 groups/100 km’ and an abundance estimate of 3,982 (95% C.I. 2,567-6,177). Combining all years and areas yielded an uncorrected density estimate of 3.82 porpoises per 100 km2, resulting in an abundance estimate of 8,940 porpoises (CV = 13.8%) with a 95% confidence interval of 6,746-11,848. Using correction factors from other studies to adjust for animals missed by observers, the total number of Alaska harbor porpoises is probably three times this number. |
format |
Text |
author |
Dahlheim, M. York, A. Towell, R. Waite, J. Breiwick, J. |
author_facet |
Dahlheim, M. York, A. Towell, R. Waite, J. Breiwick, J. |
author_sort |
Dahlheim, M. |
title |
Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993 |
title_short |
Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993 |
title_full |
Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993 |
title_fullStr |
Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993 |
title_full_unstemmed |
Harbor Porpoise ( Phocoena phocoena ) Abundance in Alaska: Bristol Bay to Southeast Alaska, 1991-1993 |
title_sort |
harbor porpoise ( phocoena phocoena ) abundance in alaska: bristol bay to southeast alaska, 1991-1993 |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2000 |
url |
https://digitalcommons.unl.edu/usdeptcommercepub/173 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1173/viewcontent/Dahlheim_MMS_2000_Harbor_porpoise.pdf |
long_lat |
ENVELOPE(-132.003,-132.003,54.416,54.416) |
geographic |
Bering Sea Dixon Entrance |
geographic_facet |
Bering Sea Dixon Entrance |
genre |
Bering Sea Kodiak Phocoena phocoena Alaska |
genre_facet |
Bering Sea Kodiak Phocoena phocoena Alaska |
op_source |
Publications, Agencies and Staff of the U.S. Department of Commerce |
op_relation |
https://digitalcommons.unl.edu/usdeptcommercepub/173 https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1173/viewcontent/Dahlheim_MMS_2000_Harbor_porpoise.pdf |
_version_ |
1782332644590092288 |