Dataset

NMML Harbor Porpoise Aerial Survey, Bristol Bay, Replicate 2, 1991

OBIS-SEAMAP Open in mapper Explore occurrences

Original provider: National Marine Mammal Laboratory Dataset credits: National Marine Mammal Laboratory Abstract: From 4 to 13 August 1991, as part of a larger study, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during an aerial survey throughout the coastal waters of Bristol Bay. A Twin Otter was used as the survey platform and was flown at an altitude of 152.2 m (500 ft) and at an airspeed of 185 km/h. The second of three identical sawtooth tracklines was flown along the south side of Bristol Bay. 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 for Bristol Bay was 1.17 (SE = 0.35) and 4.48 groups/100 km2 (SE = 1.38).

Citation: Goetz, K. and J. Waite. 2004. NMML Harbor Porpoise Aerial Survey, Bristol Bay, Replicate 2, 1991. Version 1.7.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/759822c2.

Published: October 07, 2025 at 18:31

URL: http://ipt.env.duke.edu/resource?r=zd_129

10
occurrence records
3
taxa
3
species

Taxa

Missing and invalid fields

Field Missing Invalid
coordinateUncertaintyInMeters 10
100.0%
maximumDepthInMeters 10
100.0%
minimumDepthInMeters 10
100.0%

Quality flags

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

Flag Dropped Records
NO_DEPTH 10
100.0%

Measurement types

DNA derived data