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Short Citation:
Alaska Fisheries Science Center, 2023: AFSC/MML: Distribution and abundance of Southeast Alaska harbor porpoise, 2019,

Item Identification

Title: AFSC/MML: Distribution and abundance of Southeast Alaska harbor porpoise, 2019
Status: Completed
Creation Date: 2019
Publication Date: 2023

As currently defined, the Southeast Alaska (SEAK) harbor porpoise (Phocoena phocoena) stock ranges from Dixon entrance to Cape Suckling, including inland waterways. Since the early 1990s, the Marine Mammal Laboratory (MML) has conducted ship and aerial surveys to assess abundance and status of harbor porpoise in this region (Dahlheim et al., 2009; Hobbs and Waite, 2010). In recent years, analysis of ship survey sighting data from inland waters has indicated the potential for substructure within this stock. Trends in abundance between 1991 and 2012 suggested that numbers of harbor porpoise in the northern portion of the study area (Glacier Bay/Icy Strait) were stable. However, in the southern portion of the range (Wrangell and Zarembo), numbers declined significantly in the mid-2000s and subsequently increased again in early 2010 (Dahlheim et al., 2015). The decline was observed only in a region where gillnet fisheries operate. Such contrasting trends in abundance between the northern and southern portions of the range suggest the possible existence of multiple populations within the currently recognized SEAK stock.

There is evidence that incidental mortality of harbor porpoise in the salmon driftnet fishery in SEAK may exceed the maximum allowable level under the Marine Mammal Protection Act (MMPA) (Muto et al., 2018). The most recent estimate of abundance for the whole stock is more than 8 years old and cannot be used to estimate PBR. In addition, estimates of abundance from inland waters from 2011 are now outdated and are no longer applicable for management. Therefore, a new estimate was needed to update estimates of the maximum allowable bycatch levels.


The purpose of this ship survey was to assess distribution of harbor porpoise in inland waters of SEAK, including areas never previously surveyed by the MML cruises, and to collect visual line transect survey data to compute a new estimate of abundance.


Theme Keywords

Thesaurus Keyword
ISO 19115 Topic Category
ISO 19115 Topic Category
World Register of Marine Species (WoRMS)
Phocoena phocoena View WoRMS Aphia Record
None Abundance estimate
None Distance sampling
None Line transect

Temporal Keywords

Thesaurus Keyword
None Summer

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords

Physical Location

Organization: National Marine Mammal Laboratory
City: Seattle
State/Province: WA

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Spreadsheet
Maintenance Frequency: None Planned
Data Presentation Form: Table (digital)

Support Roles

Data Steward

CC ID: 1222474
Date Effective From: 2019
Date Effective To:
Contact (Person): Zerbini, Alexandre
Email Address:


CC ID: 1222475
Date Effective From: 2016-03-23
Date Effective To:
Contact (Organization): National Centers for Environmental Information - Silver Spring, Maryland (NCEI-MD)
Address: NOAA/NESDIS E/OC SSMC3, 4th Floor, 1351 East-West Highway
Silver Spring, MD 20910-3282
Phone: (301) 713-3277

Metadata Contact

CC ID: 1222476
Date Effective From: 2016-03-23
Date Effective To:
Contact (Person): MC, Metadata Coordinators
Email Address:


CC ID: 1222477
Date Effective From: 2016-03-23
Date Effective To:
Contact (Organization): Alaska Fisheries Science Center (AFSC)
Address: 7600 Sand Point Way N.E., Building 4
Seattle, WA 98115
Business Hours: 0700-1700 Pacific Time

Point of Contact

CC ID: 1222478
Date Effective From: 2016-03-23
Date Effective To:
Contact (Person): Angliss, Robyn
Address: 7600 Sand Point Way, NE
Seattle, WA 98115-6349
Email Address:
Phone: 206-526-4032
Fax: 206-526-6615


Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1221979
W° Bound: -137.16666666667
E° Bound: -131
N° Bound: 59.5
S° Bound: 54.5

Extent Group 1 / Geographic Area 2

CC ID: 1221980

Southeast Alaska

Extent Group 1 / Time Frame 1

CC ID: 1222483
Time Frame Type: Range
Start: 2019-07-19
End: 2019-08-12

Access Information

Security Class: Unclassified
Data Access Constraints:

There are no legal restrictions on access to the data. They reside in public domain and can be freely distributed.

Data Use Constraints:

User must read and fully comprehend the metadata prior to use. Applications or inferences derived from the data should be carefully considered for accuracy. Acknowledgement of NOAA/NMFS/AFSC, as the source from which these data were obtained in any publications and/or other representations of these, data is suggested.

Distribution Information

Distribution 1

CC ID: 1222481
Download URL:
Distributor: National Centers for Environmental Information - Silver Spring, Maryland (NCEI-MD) (2016-03-23 - Present)
File Name: HP_SEAK_2019 dataset.csv

csv files with effort and sighting data.

File Type (Deprecated): .csv
Distribution Format: CSV - Comma Separated Values (Text)



CC ID: 1222479
Name: Estimating abundance of an elusive cetacean in a complex environment: Harbor porpoises (Phocoena phocoena) in inland waters of Southeast Alaska
URL Type:
Online Resource

Publication of abundance estimate from the 2019 harbor porpoise survey


CC ID: 1222624
Name: Identification of demographically independent populations within the currently designated Southeast Alaska harbor porpoise stock.
URL Type:
Online Resource

Publication on Southeast Alaska harbor porpoise demographically

independent populations.

Data Quality

Completeness Report:

Survey data was collected with Wincruz (Windows Real Time Sighting-Effort Event Logger developed by Robert Holland at Southwest Fisheries Science Center).

Quality Control Procedures Employed:

Accuracy was ensured by reviewing and editing the data in the field on a daily basis. Post cruise processing included data extraction and error checking using customized software (written by Paul Wade, Marine Mammal Laboratory). Tracklines and sightings were plotted in ArcMap to check for accuracy.


Lineage Statement:

Methods are described in publication:

Process Steps

Process Step 1

CC ID: 1222565


Child Items

Rubric scores updated every 15m

Rubric Score Type Title
Entity HP_SEAK_2019 dataset.csv

Catalog Details

Catalog Item ID: 69383
GUID: gov.noaa.nmfs.inport:69383
Metadata Record Created By: Janice Waite
Metadata Record Created: 2023-03-01 18:46+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2023-10-17 16:12+0000
Metadata Record Published: 2023-03-08
Owner Org: AFSC
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2023-03-08
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2024-03-08