Author: MGEL TECH
Keywords: Occurrence,Aircraft,Sightings,harbor porpoise,Phocoena phocoena,abundance,aerial survey,marine mammal survey,survey,marine mammal,cetacean, Observation, Occurrence

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

Kimberly Goetz^1, Janice Waite^2, OBIS-SEAMAP^3

1 Duke University, ; 2 National Marine Mammal Laboratory, ; 3 Marine Geospatial Ecology Lab, Duke University, A328 LSRC building, 27708, Durham, United States

Corresponding author(s): Kimberly Goetz (ktg4@duke.edu)Janice Waite (Janice.Waite@noaa.gov), OBIS-SEAMAP (seamap-contact@duke.edu)

Received {date}; Revised {date}; Accepted {date}; Published {date}

Citation: Combination of authors, year of data paper publication (in parentheses), Title, Journal Name, Volume, Issue number (in parentheses), and doi of the data paper.

Resource Citation

Dahlheim, M., A. York, R. Towell, J. Waite, and J. Breiwick. 2000. Harbor porpoise (Phocoena phocoena) abundance in Alaska: Bristol Bay to southeast Alaska, 1991-1993. Marine Mammal Science. 16(1): 28-45. http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1173&context=usdeptcommercepub

Abstract

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 (<i>Phocoena phocoena</i>) 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).

Purpose:
Although harbor porpoises, <i>Phocoena phocoena</i>, are known to occur throughout Alaska waters, few estimates of abundance exist. In 1991, the National Marine Mammal Laboratory initiated a 3 year study on Alaska harbor porpoises.  The objectives of this program were to: 
1) Obtain minimum population estimates in coastal waters using line transect methodology with a coefficient of variation for density estimates of less than 30% for each survey area, and
2) Establish a baseline for detecting changes in abundance through time, for analysis of trends. 
During the present study, it was not fiscally possible to survey all areas of the state in any one year. Accordingly, we selected sections of the state to survey in consecutive years to maximize the likelihood of including all of the animals for a particular area surveyed while minimizing the likelihood of significant movement between areas among survey years.

Supplemental information:
This dataset and associated effort data were updated on September 8, 2005. Those who downloaded them before that date should renew them.

Keywords: Occurrence,Aircraft,Sightings,harbor porpoise,Phocoena phocoena,abundance,aerial survey,marine mammal survey,survey,marine mammal,cetacean, Observation, Occurrence

General description

Purpose: Although harbor porpoises, <i>Phocoena phocoena</i>, are known to occur throughout Alaska waters, few estimates of abundance exist. In 1991, the National Marine Mammal Laboratory initiated a 3 year study on Alaska harbor porpoises.  The objectives of this program were to: 
1) Obtain minimum population estimates in coastal waters using line transect methodology with a coefficient of variation for density estimates of less than 30% for each survey area, and
2) Establish a baseline for detecting changes in abundance through time, for analysis of trends. 
During the present study, it was not fiscally possible to survey all areas of the state in any one year. Accordingly, we selected sections of the state to survey in consecutive years to maximize the likelihood of including all of the animals for a particular area surveyed while minimizing the likelihood of significant movement between areas among survey years.
Additional information: marine, harvested by iOBIS

Project details

Project title: NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992
Personnel: Kimberly Goetz, Janice Waite
Funding: NA

Data published through GBIF: http://ipt.env.duke.edu/resource?r=zd_136

Taxonomic coverage

General taxonomic coverage description: Scientific names are based on the Integrated Taxonomic Information System (ITIS).
Taxonomic ranks
Order: Cetacea, Cetacea
Species: Phocoenoides dalli, Balaenoptera physalus, Phocoena phocoena
Common names: Dall's Porpoise, Fin Whale, Harbor Porpoise, cetaceans, cetaceans

Spatial coverage

General spatial coverage: Alaska Peninsula,Alaska
Coordinates: 55°18'50.4''N and 57°38'16.8''N Latitude; 159°56'9.6''W and 154°43'55.2''W Longitude 

Temporal coverage: July 31, 1992

Natural collections description

Parent collection identifier: OBIS-SEAMAP
Collection name: zd_136
Collection identifier: zd_136

Methods

Method step description: NA
Study extent description: NA
Sampling description: NA

Datasets

Dataset description
Object name: Darwin Core Archive NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992
Character encoding: UTF-8
Format name: Darwin Core Archive format
Format version: 1.0
Distribution: http://ipt.env.duke.edu/archive.do?r=zd_136
Publication date of data: 2021-04-24
Language: English
Licences of use: Creative Commons Attribution Non Commercial (CC-BY-NC) 4.0 License

External datasets

Dataset description
Object name: OBIS-SEAMAP Dataset Page
Character encoding: UTF-8
Format name: Interactive map
Distribution: http://seamap.env.duke.edu/dataset/136

Dataset description
Object name: FGDC Metadata
Character encoding: UTF-8
Format name: XML
Distribution: http://seamap.env.duke.edu/dataset/136/xml

Metadata language: English
Date of metadata creation: 2014-06-17
Hierarchy level: Dataset