Beluga, Delphinapterus leucas, Habitat Associations in Cook Inlet, Alaska

Moore, Sue E. and Shelden , Kim E. W. and Litzky, Laura K. and Mahoney, Barbara A. and Rugh, David J. (2000) Beluga, Delphinapterus leucas, Habitat Associations in Cook Inlet, Alaska. Marine Fisheries Review, 62(3), pp. 60-80.

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A review of available information describing habitat associations for belugas, Delphinapterus leucas, in Cook Inlet was undertaken to complement population assessment surveys from 1993-2000. Available data for physical, biological, and anthropogenic factors in Cook Inlet are summarized followed by a provisional description of seasonal habitat associations. To summarize habitat preferences, the beluga summer distribution pattern was used to partition Cook Inlet into three regions. In general, belugas congregate in shallow, relatively warm, low-salinity water near major river outflows in upper Cook Inlet during summer (defined as their primary habitat), where prey availability is comparatively high and predator occurrence relatively low. In winter, belugas are seen in the central inlet, but sightings are fewer in number, and whales more dispersed compared to summer. Belugas are associated with a range of ice conditions in winter, from ice-free to 60% ice-covered water. Natural catastrophic events, such as fires, earthquakes, and volcanic eruptions, have had no reported effect on beluga habitat, although such events likely affect water quality and, potentially, prey availability. Similarly, although sewage effluent and discharges from industrial and military activities along Cook Inlet negatively affect water quality, analyses of organochlorines and heavy metal burdens indicate that Cook Inlet belugas are not assimilating contaminant loads greater than any other Alaska beluga stocks. Offshore oil and gas activities and vessel traffic are high in the central inlet compared with other Alaska waters, although belugas in Cook Inlet seem habituated to these anthropogenic factors. Anthropogenic factors that have the highest potential negative impacts on belugas include subsistence hunts (not discussed in this report), noise from transportation and offshore oil and gas extraction (ship transits and aircraft overflights), and water quality degradation (from urban runoff and sewage treatment facilities). Although significant impacts from anthropogenic factors other than hunting are not yet apparent, assessment of potential impacts from human activities, especially those that may effect prey availability, are needed.

Item Type: Article
Title: Beluga, Delphinapterus leucas, Habitat Associations in Cook Inlet, Alaska
Personal Creator/Author:
Moore, Sue E.
Shelden , Kim E. W.
Litzky, Laura K.
Mahoney, Barbara A.
Rugh, David J.
Refereed: Yes
Journal or Publication Title: Marine Fisheries Review
Volume: 62
Number: 3
Page Range: pp. 60-80
Date: 2000
ISSN: 0090-1830
Issuing Agency: United States National Marine Fisheries Service
Subjects: Biology
Item ID: 9771
Depositing User: Patti M. Marraro
Date Deposited: 14 Aug 2012 20:26
Last Modified: 08 May 2017 19:16

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