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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). Harbor porpoise (Phocoena phocoena) abundance in Alaska: Bristol Bay to southeast Alaska, 1991-1993. Mar. Mamm. Sci. 16(1): 28-45. hdl.handle.net/10.1111/j.1748-7692.2000.tb00902.x
In: Marine Mammal Science. Society for Marine Mammalogy: Lawrence, Kan.. ISSN 0824-0469, more
Peer reviewed article  

Available in Authors | Datasets 

Keywords
    Phocoena phocoena (Linnaeus, 1758) [WoRMS]; Marine
Author keywords
    harbor porpoise;Phocoena phocoena;abundance;Alaska

Authors  Top | Datasets 
  • Dahlheim, M.
  • York, A.
  • Towell, R.
  • Waite, J.
  • Breiwick, J.

Abstract
    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 km2 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.

Datasets (12)
  • NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 1, 1992, more
  • NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992, more
  • NMML Harbor Porpoise Aerial Survey, Bristol Bay, Replicate 1, 1991, more
  • NMML Harbor Porpoise Aerial Survey, Bristol Bay, Replicate 2, 1991, more
  • NMML Harbor Porpoise Aerial Survey, Bristol Bay, Replicate 3, 1991, more
  • NMML Harbor Porpoise Aerial Survey, Cook Inlet, 1991, more
  • NMML Harbor Porpoise Aerial Survey, Kodiak Island, Replicate 1, 1992, more
  • NMML Harbor Porpoise Aerial Survey, Kodiak Island, Replicate 2, 1992, more
  • NMML Harbor Porpoise Aerial Survey, SE Alaska, 1991, more
  • NMML Harbor Porpoise Aerial Survey, SE Alaska, Replicate 1, 1993, more
  • NMML Harbor Porpoise Aerial Survey, SE Alaska, Replicate 2, 1993, more
  • NMML Harbor Porpoise Aerial Survey, SE Alaska, Replicate 3, 1993, more

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