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NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992
Entry ID: seamap136

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Summary
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 saw-tooth tracklines was flown at
an altitude of 152.2 m (500ft) and at an airspeed of 100 kn. 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 = .10) and 2.03 groups/100 km^2
(SE=1.65).


Purpose: Although harbor porpoises, Phocoena phocoena, are known to occur
throughout Alaska waters (Fiscus et al. 1976; Leatherwood and Reeves 1978;
Lawry et al. 1982; Leatherwood et al. 1983), few estimates of abundance exist.
In 1991, the National Marine Mammal Laboratory initiated a 3-yr 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. 2) Establish a baseline for detecting changes in abundance through time,
for analysis of trends.

SUPPLEMENTAL INFORMATION: Note: This dataset and associated effort data was
updated on Sept 8, 2005. Those who downloaded them before that date should
renew them. 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.

CURRENTNESS REFERENCE: ground condition

SPATIAL REFERENCE INFORMATION -
GEODETIC MODEL
Horizontal Datum Name: D_WGS_1984
Ellipsoid Name: WGS_1984
Semi-major Axis: 6378137.000000
Denominator of Flattening Ratio: 298.257224

Related URL
Link: GET DATA
Link: GET DATA
Description: Access data from the OBIS and OBIS-SEAMAP websites.


Link: GET SERVICE > ACCESS MAP VIEWER
Description: OBIS-SEAMAP Map Service


Link: VIEW EXTENDED METADATA


Link: VIEW PROJECT HOME PAGE
Description: Ocean Biogeographic Information System - Spatial Ecological Analysis of
Megavertebrate Populations (OBIS-SEAMAP)


Link: VIEW PROJECT HOME PAGE
Description: Ocean Biogeographic Information System (OBIS)


Link: VIEW RELATED INFORMATION
Description: Biological Data Profile


Link: VIEW RELATED INFORMATION
Description: ESRI Metadata Profile


Parent DIF
This description is a member of a collection. The collection is described in
OBIS-SEAMAP


Geographic Coverage
 N: 57.63767 S: 55.314  E: -154.73167  W: -159.93567

Data Set Citation
Dataset Originator/Creator: National Marine Mammal Laboratory
Dataset Title: NMML Harbor Porpoise Aerial Survey, Alaska Peninsula, Replicate 2, 1992
Dataset Series Name: OBIS-SEAMAP
Dataset Release Date: 2004-08-09 16:49:12.466317-04
Dataset Release Place: http://seamap.env.duke.edu/
Dataset Publisher: OBIS-SEAMAP
Data Presentation Form: vector digital data
Online Resource: http://nmml.afsc.noaa.gov/


Temporal Coverage
Start Date: 1992-07-31
Stop Date: 1992-07-31


Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > ALASKA > ALASKA PENINSULA


Data Resolution
Latitude Resolution: 0.000167 Decimal degrees
Longitude Resolution: 0.000167 Decimal degrees


Science Keywords
BIOLOGICAL CLASSIFICATION >ANIMALS/VERTEBRATES    [Definition]
BIOLOGICAL CLASSIFICATION >ANIMALS/VERTEBRATES >FISH    [Definition]


ISO Topic Category
BIOTA
BOUNDARIES


Platform
DHC-6 >DeHavilland Twin Otter    [Information]


Project
OBIS-SEAMAP >OBIS - Spatial Ecological Analysis of Megavertebrate Populations    [Information]


Access Constraints
ACCESS CONSTRAINTS: Open public unless otherwise noted.

DISTRIBUTION LIABILITY: Not to hold OBIS-SEAMAP liable for errors in the data.
While we have made every effort to ensure the quality of the database, we
cannot guarantee the accuracy of these datasets. Also please refer to Use
Constraints.


Use Constraints
Not to use data contained in OBIS-SEAMAP in any publication, product, or
commercial application without prior written consent of the original data
provider. To cite both the data provider and OBIS-SEAMAP appropriately after
approval of use is obtained. Also please refer to Distribution Liability.


Keywords
abundance
aerial survey
baleia
baleines
Ballena de aleta
ceo
cetacean
cetaceans
common porpoise
Dall's porpoise
dauphins
dolphins
finback whale
fin whale
golfinho
harbor porpoise
marine mammal
marine mammals
marine mammal survey
Marsopa de Dall
marsouin commun
marsouins
Phocoena phocoena
porpoises
res marins
rorqual commun
survey
True's porpoise
whales


Data Set Progress
COMPLETE


Data Center
OBIS Spatial Ecological Analysis of Megavertebrate Populations    [Information]
Data Center URL: http://seamap.env.duke.edu/

Data Center Personnel
Name: PATRICK N. HALPIN
Phone: 919-613-8062
Email: phalpin at duke.edu
Contact Address:
Duke University
Box 90328
City: Durham
Province or State: NC
Postal Code: 27708
Country: USA



Distribution
Distribution_Format: Shapefile


Personnel
EI FUJIOKA
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Phone: 919-613-8021
Fax: 919-684-8741
Email: efujioka at duke.edu
Contact Address:
LSRC A321
Box 90328
City: Durham
Province or State: NC
Postal Code: 27708
Country: USA


JANICE WAITE
Role: TECHNICAL CONTACT
Phone: 206-526-6554
Email: Janice.Waite at noaa.gov
Contact Address:
NATIONAL MARINE MAMMAL LABORATORY
7600 Sand Point Way N.E.
City: Seattle
Province or State: Washington
Postal Code: 98115-6349
Country: USA


Publications/References
M. Dahlheim et al. Harbor porpoise (Phocoena phocoena) abundance in Alaska:
Bristol Bay to Southeast Alaska, 1991-1993. 2000. Marine Mammal Science. 16(1):
28-45.

Creation and Review Dates
DIF Creation Date: 2007-01-22
Last DIF Revision Date: 2016-01-27



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