AFSC/NMML: Beluga whale aerial survey in Cook Inlet, Alaska, 1993-2022

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Data can be accessed at http://data.nodc.noaa.gov/cgi-bin/iso?id=gov.noaa.nodc:0133936.

There are no legal restrictions on access to the data. They reside in public domain and can be freely distributed.

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.

Access

Two observers were positioned on the shoreward side of the plane and one observer and a data recorder on the offshore side. During many of the surveys, an intercom system provided communication among the observers, data recorder, and pilots, but a selective listening device was used to aurally isolate each observer position. This ensured independent sighting collection to calculate correction factors for missed beluga groups. After reporting a beluga group, the team would go off effort and the plane would fly directly over the group to obtain a sighting location. A racetrack pattern was flown around the whale aggregation and the paired observers would tally the number of animals independently and assign an overall grade to the circling pass (A to F for excellent to poor). The pass quality was based on the overall visibility of the group (accounting for sea state, sighting distance, glare, and the condition of the observation window), irrespective of the number of whales at the surface. Once the two observers recorded four high quality passes (A or B), the crew would rotate and the remaining observer and data recorder would count until they also obtained four high quality passes. In most cases, there were 16 high quality counts for each group of belugas encountered. The number of counting passes was occasionally reduced when group sizes were small (less than 10 animals) or when air traffic precluded additional circling time. All data were recorded real-time into a Microsoft Access database by a specially-designed software program. Edits were performed at the end of each survey day for quality control purposes.

All sighting data for species other than beluga whales were collected opportunistically and should be used with caution. On rare occasions (pre 2005) the GPS lost signal resulting in data gaps in the trackline data.

After each survey day, data were quality controlled by checking all hand entered information from that day including weather, sightings, species, group sizes, observer position, and comment data for errors.

IT Security and Contingency Plan for the system establishes procedures and applies to the functions, operations, and resources necessary to recover and restore data as hosted in the Western Regional Support Center in Seattle, Washington, following a disruption.