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    • AFSC/NMML: Bowhead Whale Aerial Abundance Survey off Barrow, Alaska, Spring 2011

    Metadata Updated: November 1, 2024

    Aerial photographic surveys for bowhead whales were conducted near Point Barrow, Alaska, from 19 April to 6 June in 2011. Approximately 4,594 photographs containing 6,801 bowhead whale images were obtained (not accounting for resightings). The 2011 field season was very successful: we flew 36 out of 49 available days and conducted 49 flights in that time; we were grounded due to weather on 13 days. The longest period of time that we were grounded due to weather (low ceilings/fog) was three days. This occurred after the migration had slowed down, during a time when few whales passed the ice perches according to the ice-based visual survey. The 2011 migration was steady with several peaks (30 April, 4-5 May, 12 May), and then the migration rate slowed down considerably after 14 May. The photographs taken in 2011 are a significant contribution to the bowhead whale photographic catalogue. They will be used to calculate a population estimate that may be used for comparison with the 2011 ice-based estimate and will provide better precision in estimates of bowhead whale life-history parameters.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date October 3, 2024
    Metadata Created Date October 28, 2022
    Metadata Updated Date November 1, 2024
    Reference Date(s) 2011 (creation), (publication)
    Frequency Of Update notPlanned

    Metadata Source

    Harvested from NMFS AFSC

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Date October 3, 2024
    Metadata Created Date October 28, 2022
    Metadata Updated Date November 1, 2024
    Reference Date(s) 2011 (creation), (publication)
    Responsible Party (Point of Contact, Custodian)
    Contact Email
    Guid gov.noaa.nmfs.inport:17334
    Access Constraints Cite As: Alaska Fisheries Science Center, [Date of Access]: AFSC/NMML: Bowhead Whale Aerial Abundance Survey off Barrow, Alaska, Spring 2011 [Data Date Range], https://www.fisheries.noaa.gov/inport/item/17334., Access Constraints: There are no legal restrictions on access to the data. They reside in public domain and can be freely distributed., Use Constraints: User must read and fully comprehend the metadata prior to use. Applications or inferences derived from the data should be carefully considered for accuracy. Acknowledgement of NOAA/NMFS/AFSC, as the source from which these data were obtained in any publications and/or other representations of these, data is suggested., Distribution Liability: The user is responsible for the results of any application of this data for other than its intended purpose. NOAA denies liability if the data are misused.
    Bbox East Long -148
    Bbox North Lat 72
    Bbox South Lat 68
    Bbox West Long -165
    Coupled Resource
    Frequency Of Update notPlanned
    Harvest Object Id 1c0d51c7-67b8-4b4a-bab3-6d24ef8b01c6
    Harvest Source Id 26a29bb9-50b0-47fd-920b-edc74aa6ec76
    Harvest Source Title NMFS AFSC
    Licence NOAA provides no warranty, nor accepts any liability occurring from any incomplete, incorrect, or misleading data, or from any incorrect, incomplete, or misleading use of the data. It is the responsibility of the user to determine whether or not the data is suitable for the intended purpose.
    Lineage The 2011 spring aerial abundance survey was conducted jointly by the North Slope Borough Department of Wildlife Management (NSB-DWM) and the National Marine Mammal Laboratory (NMML). Methodology was similar to earlier studies (Koski et al. 1992; Angliss et al. 1995). Surveys were conducted in an Aero Commander 690 with bubble windows in the two forward observer positions. The aircraft flew at an average air speed of ~217km/h (117kts) and altitude of 200m (656ft), and flew directly over bowhead whales during photographic passes. Photographs were taken with a Canon Mark III-1DS digital camera affixed with a Zeiss 85mm fixed f/1.4 Planar T* lens pointed directly downward through the aircraft's ventral camera port that was covered with optical quality glass. Shutter speed was typically 1/2500th second or faster. Aircraft altitude was recorded every 2 seconds with a portable Garmin 76CSx GPS unit and saved on a laptop computer. Robogeo software was used to embed latitude, longitude and altitude into the Exif metadata of each photograph. Calibration targets of known dimensions were photographed twice during the season, at the beginning and end of the survey. These calibration photographs were taken from the same altitudes flown during survey effort. Additionally, each flight began with a photographic pass over a table of known dimensions at a set altitude of 152m (500ft) to act as a daily check of altimeter performance.
    Metadata Language eng
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-165.0, 68.0], [-148.0, 68.0], [-148.0, 72.0], [-165.0, 72.0], [-165.0, 68.0]]]}
    Progress completed
    Spatial Data Service Type
    Spatial Reference System
    Spatial Harvester True
    Temporal Extent Begin 2011-04-01
    Temporal Extent End 2011-06-01

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