Dataset

NMML Harbor Porpoise Aerial Survey, SE Alaska, Replicate 3, 1993

OBIS-SEAMAP Open in mapper Explore occurrences

Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: On 1 to 26 June 1993, as part of a larger study, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during an aerial survey from Prince William Sound to Dixon Entrance. Employing a Twin Otter as the survey platform, the third of three identical sawtooth tracklines was flown at an altitude of 152.2 m (500 ft) and at an airspeed of 185 km/h. Line-transect methodology was used, and only those observations made during optimal conditions were analyzed. Density of harbor porpoises was calculated using line transect estimates based on perpendicular distances of sightings to the cruise track of the airplane. On average, porpoise group size and density from Prince William Sound to Dixon Entrance was 1.22 (SE = 0.04) and 4.02 groups/100 km2 (SE = 7.42).

Citation: Goetz, K. and J. Waite. 2010. NMML Harbor Porpoise Aerial Survey, SE Alaska, Replicate 3, 1993. Version 1.7.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/a14ae756.

Published: October 07, 2025 at 19:00

URL: http://ipt.env.duke.edu/resource?r=zd_141

165
occurrence records
6
taxa
5
species

Taxa

Missing and invalid fields

Field Missing Invalid
coordinateUncertaintyInMeters 165
100.0%
maximumDepthInMeters 165
100.0%
minimumDepthInMeters 165
100.0%

Quality flags

The OBIS data quality flags are documented at https://github.com/iobis/obis-qc.

Flag Dropped Records
NO_DEPTH 165
100.0%
ON_LAND 1
0.6%

Measurement types

DNA derived data