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

• Main Authors: Goetz, Kimberly, Waite, Janice
• Format: Dataset
• Language: English
• Published: OBIS-SEAMAP 2021
• Subjects: Occurrence,Aircraft,Sightings,harbor porpoise,Phocoena phocoena,abundance,aerial survey,marine mammal survey,survey,marine mammal,cetacean; Observation; Occurrence; Dixon Entrance; Phocoena phocoena; Alaska
• Online Access: https://dx.doi.org/10.15468/umkh3y; https://www.gbif.org/dataset/6eea7c9e-2312-41e5-a11a-fe000fe0e84b

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). Purpose: Although harbor porpoises, Phocoena phocoena , are known to occur throughout Alaska waters, few estimates of abundance exist. ...