Dataset

NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992

OBIS-SEAMAP Open in mapper Explore occurrences

Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: On 6 July to 9 August 1992, as part of a larger study, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during an aerial survey off the south side of the Alaska Peninsula. Employing a Twin Otter as the survey platform, the second of two 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 off the south side of the Alaska Peninsula was 1.1 (SE = 0.10) and 2.03 groups/100 km2 (SE = 1.65).

Citation: Goetz, K. and J. Waite. 2004. NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992. Version 1.7.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/77b21a7c.

Published: October 07, 2025 at 18:59

URL: http://ipt.env.duke.edu/resource?r=zd_136

41
occurrence records
4
taxa
3
species

Taxa

Missing and invalid fields

Field Missing Invalid
coordinateUncertaintyInMeters 41
100.0%
maximumDepthInMeters 41
100.0%
minimumDepthInMeters 41
100.0%

Quality flags

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

Flag Dropped Records
NO_DEPTH 41
100.0%

Measurement types

DNA derived data