Pacific Walrus Coastal Haulout Images from Carcass Surveys

Identification_Information:

Citation:

Citation_Information:

Originator: Fischbach, Anthony S. (ORCID: 0000-0002-6555-865X)
Publication_Date: 20240221
Title: Pacific Walrus Coastal Haulout Images from Carcass Surveys
Geospatial_Data_Presentation_Form: digital photos, tabular digital data
Publication_Information:

Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center

Other_Citation_Details:

Suggested Citation: Fischbach, A.S., 2024. Pacific walrus coastal haulout images from carcass surveys: U.S. Geological Survey data release, https://doi.org/10.5066/P1QZNNUY

Online_Linkage: https://doi.org/10.5066/P1QZNNUY
Larger_Work_Citation:

Citation_Information:

Originator: U.S. Geological Survey, Alaska Science Center
Publication_Date: 2005
Title:

Response of Pacific Walrus Populations to a Rapidly Diminishing Sea Ice Environment

Geospatial_Data_Presentation_Form: website
Series_Information:

Series_Name: Alaska Science Portal
Issue_Identification: 96

Publication_Information:

Publication_Place: Anchorage, Alaska
Publisher: U.S. Geological Survey, Alaska Science Center

Other_Citation_Details:

This is a link to the broader USGS Alaska Science Center research project supported by these data. Users will find a description of the research project and links to associated reports, publications, and data products.

Online_Linkage: https://alaska.usgs.gov/portal/project.php?project_id=96

Description:

Abstract:

This data package contains digital images, survey location logs and a summary tabulation from carcass survey conducted at walrus haulouts in Alaska. A summary of image collection times is provided as a tabular file.

Purpose:

The carcass surveys were collected for the purpose of evaluating whether satellite imagery could be interpreted to detect walrus carcasses.

Supplemental_Information:

The images are considered sensitive. They are archived at the U.S. Geological Survey, Alaska Science Center (a USGS Trusted Digital Repository). At this time, only this metadata record describing the data, an image inventory table, and a satellite (GNSS) log are publicly accessible.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 2023
Ending_Date: 2023

Currentness_Reference: observed

Status:

Progress: In work
Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Description_of_Geographic_Extent:

Chukchi Sea coast of the Kasekaluk Lagoon barrier island near Point Lay, Alaska

Bounding_Coordinates:

West_Bounding_Coordinate: -163.817
East_Bounding_Coordinate: -160.752
North_Bounding_Coordinate: 69.147
South_Bounding_Coordinate: 70.422

Keywords:

Theme:

Theme_Keyword_Thesaurus: USGS Metadata Identifier
Theme_Keyword: USGS:ASC600

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: Biota
Theme_Keyword: Environment

Theme:

Theme_Keyword_Thesaurus: NASA GCMD Earth Science Keyword Thesaurus
Theme_Keyword: Animals/vertebrates
Theme_Keyword: Mammals
Theme_Keyword: Carnivores
Theme_Keyword: Seals/sea lions/walruses

Theme:

Theme_Keyword_Thesaurus: USGS CSA Biocomplexity Thesaurus
Theme_Keyword: Marine mammals
Theme_Keyword: Seasonal distribution

Theme:

Theme_Keyword_Thesaurus: USGS Thesaurus
Theme_Keyword: Wildlife
Theme_Keyword: Migratory species
Theme_Keyword: Marine ecosystems
Theme_Keyword: Coastal ecosystems
Theme_Keyword: Remote sensing
Theme_Keyword: Image collections
Theme_Keyword: Field inventory and monitoring

Theme:

Theme_Keyword_Thesaurus: None
Theme_Keyword: Remote photo imagery
Theme_Keyword: Pinniped

Place:

Place_Keyword_Thesaurus: USGS Geographic Names Information System (GNIS)
Place_Keyword: Alaska
Place_Keyword: Chukchi Sea
Place_Keyword: Point Lay

Place:

Place_Keyword_Thesaurus: Protected Areas Database of the United States (PAD-US)
Place_Keyword: Kasekaluk Lagoon

Taxonomy:

Keywords/Taxon:

Taxonomic_Keyword_Thesaurus: None
Taxonomic_Keywords: Marine mammals
Taxonomic_Keywords: Pacific Walrus
Taxonomic_Keywords: Odobenus rosmarus divergens

Taxonomic_System:

Classification_System/Authority:

Classification_System_Citation:

Citation_Information:

Originator: ITIS Integrated Taxonomic Information System
Publication_Date: Unknown
Title: ITIS Integrated Taxonomic Information System
Geospatial_Data_Presentation_Form: online database
Publication_Information:

Publication_Place: online
Publisher: ITIS-North America

Other_Citation_Details:

Taxonomic details retrieved January 9, 2024 from the Integrated Taxonomic Information System online database https://www.itis.gov

Online_Linkage: https://doi.org/10.5066/F7KH0KBK

Taxonomic_Procedures:

Species were identified by skilled interpreters while in the field.

Taxonomic_Classification:

Taxon_Rank_Name: Kingdom
Taxon_Rank_Value: Animalia
Taxonomic_Classification:

Taxon_Rank_Name: Subkingdom
Taxon_Rank_Value: Bilateria
Taxonomic_Classification:

Taxon_Rank_Name: Infrakingdom
Taxon_Rank_Value: Deuterostomia
Taxonomic_Classification:

Taxon_Rank_Name: Phylum
Taxon_Rank_Value: Chordata
Taxonomic_Classification:

Taxon_Rank_Name: Subphylum
Taxon_Rank_Value: Vertebrata
Taxonomic_Classification:

Taxon_Rank_Name: Infraphylum
Taxon_Rank_Value: Gnathostomata
Taxonomic_Classification:

Taxon_Rank_Name: Superclass
Taxon_Rank_Value: Tetrapoda
Taxonomic_Classification:

Taxon_Rank_Name: Class
Taxon_Rank_Value: Mammalia
Taxonomic_Classification:

Taxon_Rank_Name: Subclass
Taxon_Rank_Value: Theria
Taxonomic_Classification:

Taxon_Rank_Name: Infraclass
Taxon_Rank_Value: Eutheria
Taxonomic_Classification:

Taxon_Rank_Name: Order
Taxon_Rank_Value: Carnivora
Taxonomic_Classification:

Taxon_Rank_Name: Suborder
Taxon_Rank_Value: Caniformia
Taxonomic_Classification:

Taxon_Rank_Name: Family
Taxon_Rank_Value: Odobenidae
Taxonomic_Classification:

Taxon_Rank_Name: Genus
Taxon_Rank_Value: Odobenus
Taxonomic_Classification:

Taxon_Rank_Name: Species
Taxon_Rank_Value: Odobenus rosmarus
Applicable_Common_Name: Walrus
Applicable_Common_Name: TSN: 180639
Taxonomic_Classification:

Taxon_Rank_Name: Subspecies
Taxon_Rank_Value: Odobenus rosmarus divergens
Applicable_Common_Name: Pacific Walrus
Applicable_Common_Name: TSN: 622045

Access_Constraints: None
Use_Constraints:

It is requested that the authors and the USGS Alaska Science Center be cited for any subsequent publications that reference this dataset.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: U.S. Geological Survey, Alaska Science Center

Contact_Address:

Address_Type: Mailing and Physical
Address: 4210 University Drive
City: Anchorage
State_or_Province: Alaska
Postal_Code: 99508
Country: USA

Contact_Voice_Telephone: 907-786-7000
Contact_Electronic_Mail_Address: ascweb@usgs.gov

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:

Data are digital images, GPS locations of field observer tracklines, and information derived from digital images.

Logical_Consistency_Report: Attribute values fall within expected ranges.
Completeness_Report: No data were omitted.
Lineage:

Methodology:

Methodology_Type: Field
Methodology_Description:

The author walked and surveyed locations where walruses had been observed resting on shore under the guidance of an experienced Inupiaq walrus hunter. During the survey, a location log was collected using a global navigation satellite system (GNSS) receiver and images were collected of walrus carcasses and objects that may be mistaken for walrus carcasses when interpreting satellite imagery. A clock running during the survey was synchronized with the GNSS receiver clock prior to the survey to enable geolocation of the images from the GNSS survey log. The survey route lines were followed ad hoc to enable a full visual survey of the barrier island between the ocean side beach and the lagoon shore. If snow covered the surveyed region, the survey route lines were taken closer to each other to ensure that any lump of interest hidden by snow would be readily visible and could be inspected by physically removing snow to reveal the nature of the lump through visible inspection. When photographing surveyed objects, the GNSS receiver was placed directly on top of the object to obtain a representative centroid location for the object.

Methodology:

Methodology_Type: Lab
Methodology_Description:

After the survey, each image was assigned metadata in an exchangeable image file format (EXIF), which described the image location as well as the nature of the objects apparent in the image.

Process_Step:

Process_Description:

The geographic location of the object centroid in the image was determined by linking the image collection time to the survey location log using EXIFTools (version 12.68) available through the GeoSetter (version 3.5.3, https://geosetter.de/ accessed 30 November 2023). EXIF keywords indicating the nature of objects apparent in the image were applied using Adobe Photoshop Lightroom class software (13.1). EXIF metadata were extracted from the images using a desktop GIS (QGIS version 3.34) to construct a tabular summary whereby each image was represented by a row and each characteristic was represented by a column in the table.

Process_Date: Unknown

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Point

Spatial_Reference_Information:

Horizontal_Coordinate_System_Definition:

Geographic:

Latitude_Resolution: 0.0000001
Longitude_Resolution: 0.0000001
Geographic_Coordinate_Units: Decimal degrees

Geodetic_Model:

Horizontal_Datum_Name: World Geodetic System of 1984 (WGS84)
Ellipsoid_Name: World Geodetic System of 1984 (WGS84)
Semi-major_Axis: 6378137
Denominator_of_Flattening_Ratio: 298.257223563

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: walrus_HauloutCarcassImages [Folder]
Entity_Type_Definition:

Folder, with subfolders, containing digital images (JPG format) from a carcass survey at haulout sites. The location of the images and the year collected are indicated by the subfolder folder name (e.g. PointLay_2023).

File naming convention: IMG_[YYYYMMDD]_[HHMMSSSSS].jpg, where [YYYYMMDD] = date the image was taken and [HHMMSSSSS] = the time the image was taken.

Entity_Type_Definition_Source: Author defined

Detailed_Description:

Entity_Type:

Entity_Type_Label: walrus_HauloutCarcassImages_GNSS_log.csv
Entity_Type_Definition:

Table of location logs obtained during on-the-ground carcass surveys using a GNSS receiver (Bad Elf Flex® Mini; nominal accuracy of 2m or better). Presented in a Comma Separated Value (CSV) formatted table.

Bad Elf Flex® Mini model: BE-GPS-2500 firmwareVersion: 1.0.13.1233 hardwareVersion: 25.1.1 Bad Elf, LLC West Hartford, Connecticut

Entity_Type_Definition_Source: Author defined

Attribute:

Attribute_Label: date_time_utc
Attribute_Definition: The date and time the location was received, in UTC.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain: The date and time the location was received, in UTC.

Attribute:

Attribute_Label: latitude
Attribute_Definition:

The latitude of the location that was received, in decimal degrees.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 69.7615418
Range_Domain_Maximum: 69.7680436
Attribute_Units_of_Measure: Decimal degrees

Attribute:

Attribute_Label: longitude
Attribute_Definition:

The longitude of the location that was received, in decimal degrees.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: -163.0533078
Range_Domain_Maximum: -163.0473803
Attribute_Units_of_Measure: Decimal degrees

Attribute:

Attribute_Label: elevation_msl
Attribute_Definition: The GNSS estimated elevation above mean sea level, in meters.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: -7.77
Range_Domain_Maximum: 7.77
Attribute_Units_of_Measure: Meters

Attribute:

Attribute_Label: horizontal_dilution_of_precision
Attribute_Definition:

The GNSS estimated horizontal dilution of precision, in meters. This value describes the error caused by the relative position of the GPS satellites.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0.35
Range_Domain_Maximum: 0.46
Attribute_Units_of_Measure: Meters

Attribute:

Attribute_Label: horizontal_circular_error_probability
Attribute_Definition:

GNSS horizontal circular error probability, in meters, based on the standard probibility value of 0.50. This value is determined by the number of points within a certain distance of a specific location as a percentage of the total number of points.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 1.330
Range_Domain_Maximum: 1.748
Attribute_Units_of_Measure: Meters

Attribute:

Attribute_Label: location_type
Attribute_Definition:

The classification for the location type estimate calculated by the GNSS.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 3D
Enumerated_Domain_Value_Definition:

The GNSS calculated the location using signals from GNSS satellites alone.

Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: SBAS
Enumerated_Domain_Value_Definition:

The GNSS receiver calculated the location using signals received from GNSS satellites and from satellite-based augmentation system.

Enumerated_Domain_Value_Definition_Source: Author defined

Detailed_Description:

Entity_Type:

Entity_Type_Label: walrus_HauloutCarcassImages_inventory.csv
Entity_Type_Definition:

Tabular summary of digital imagery from the walrus carcass surveys. Presented in a Comma Separated Value (CSV) formatted table.

Entity_Type_Definition_Source: Author defined

Attribute:

Attribute_Label: image_name
Attribute_Definition:

Name of each image as formatted and written by the survey camera. The name contains the time when the image was collected, for example the image IMG_20231006_151057650.jpg was collected at 2023-10-06 T15:10:57.650 in the local time zone (Alaska, UTC-8).

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain:

Name of each image as formatted and written by the survey camera.

Attribute:

Attribute_Label: date_time
Attribute_Definition:

Time of image collection expressed in the local timezone (Alaska, UTC-8).

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Unrepresentable_Domain:

Time of image collection expressed in the local timezone (Alaska, UTC-8).

Attribute:

Attribute_Label: latitude
Attribute_Definition:

Latitude (decimal degrees) express to six decimal figures based on table 'walrus_HauloutCarcassImages_GNSS_log.csv' included with this data release.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 69.761599
Range_Domain_Maximum: 69.768039
Attribute_Units_of_Measure: Decimal degrees

Attribute:

Attribute_Label: longitude
Attribute_Definition:

Longitude (decimal degrees) express to six decimal figures based on table 'walrus_HauloutCarcassImages_GNSS_log.csv' included with this data release.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: -163.05346
Range_Domain_Maximum: -163.04743
Attribute_Units_of_Measure: Decimal degrees

Attribute:

Attribute_Label: duplicate
Attribute_Definition:

Indicates if the record is a duplicate image of an object imaged in another record in the table.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 1
Enumerated_Domain_Value_Definition: Yes, this is a duplicate
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 0
Enumerated_Domain_Value_Definition: No, this is the primary or only image of this object
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute:

Attribute_Label: object_class
Attribute_Definition: Material of object apparent in the survey image.
Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: concrete
Enumerated_Domain_Value_Definition:

The object appears to be primarily composed of concrete, although it may also contain exposed or encased metal.

Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: gcp
Enumerated_Domain_Value_Definition:

The object is a SOLAS radar reflector that was installed in the survey area to be used as a ground control point (GCP) for adjusting the geolocation of synthetic aperture radar imagery collected by satellite.

Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: metal
Enumerated_Domain_Value_Definition: The object appears to be primarily composed of metal.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: metal_wood
Enumerated_Domain_Value_Definition: This object appears to be composed primarily of metal and wood.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: walrus
Enumerated_Domain_Value_Definition: The object appears to be a walrus carcass.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: wood
Enumerated_Domain_Value_Definition: The object appears to be primarily composed of wood.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: NA
Enumerated_Domain_Value_Definition: The material in the image was not identified as a walrus.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute:

Attribute_Label: estimated_age_class
Attribute_Definition:

If the image is a walrus, this attribute indicates the estimated age class of the individual.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: adult
Enumerated_Domain_Value_Definition:

The walrus carcass appears to be an adult based on the presence of tusks, removal of the head or overall size.

Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: calf
Enumerated_Domain_Value_Definition: This walrus carcass appears to be a calf based on overall size.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: multiple_carcasses
Enumerated_Domain_Value_Definition:

The image is of two or more carcasses involving a calf and a larger walrus in direct contact with each other.

Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: subadult
Enumerated_Domain_Value_Definition:

This walrus carcass appears to be a subadult based on the presence of very small protruding tusks and general body size.

Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: NA
Enumerated_Domain_Value_Definition: The material in the image was not identified as a walrus.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute:

Attribute_Label: carcass_state
Attribute_Definition:

If the image is a walrus, this attribute indicates the decomposition status of the carcass.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: fresh
Enumerated_Domain_Value_Definition:

This carcass appears to be from a walrus that died during the study season.

Enumerated_Domain_Value_Definition_Source: Author defined

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: NA
Enumerated_Domain_Value_Definition: The material in the image was not identified as a walrus.
Enumerated_Domain_Value_Definition_Source: Author defined

Attribute:

Attribute_Label: walrus_count
Attribute_Definition:

The total number of walrus carcasses present in the image. An 'NA' indicates that the material in the image was not identified as a walrus.

Attribute_Definition_Source: Author defined
Attribute_Domain_Values:

Range_Domain:

Range_Domain_Minimum: 0
Range_Domain_Maximum: 1
Attribute_Units_of_Measure: Count

Pacific Walrus Coastal Haulout Images from Carcass Surveys

Metadata: