Alaska Steller Sea Lion Non-pup Count Database

This database contains counts of adult and juvenile (non-pup) Steller sea lions on rookeries and haulouts in Alaska made between 1904 and 2019. Non-pup counts have been conducted throughout the year. Breeding season (June-mid July) non-pup counts are used for population trend analysis, while counts at other times are used for analyses of distribution and for other purposes. Non-pups are counted from the ground (by walking along the rookery), from cliff-side overlooks, and from aerial imagery (oblique and vertical orientation). Non-pup counts represent only a fraction of the total number of animals that may use a site. Sea lions haul-out less frequently in winter than in summer; thus, winter counts represent a smaller fraction of the total population than summer counts.

Counts of Steller sea lions pups, adults, and juveniles are used to monitor trends in the population and used in the development of population models.

Loaded by FGDC Metadata Uploader, batch 5911, 04-23-2015 19:21

The following FGDC sections are not currently supported in InPort, but were preserved and will be included in the FGDC export:

- Taxonomy (FGDC:taxonomy)

- Lineage (FGDC:lineage)

Cite data as: NMFS/AFSC/MML/Alaska Ecosystem Program (2021). Counts of Alaska Steller sea lion adult and juvenile (non-pup) conducted on rookeries and haul-outs in Alaska Aleutian Islands, Bering Sea, and others from 1904-01-01 to 2019-07-03 (NCEI Accession 0128190). NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.7289/v54f1np1. Accessed [date].

Table is comprised of Steller sea lion non-pup counts with associated spatial and temporal data.

Applications or inferences derived from the data should be carefully considered for accuracy. While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

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The data set is in the process of being archived with the NOAA National Centers for Environmental Information. Once the archival process is complete and verified, the data set will be publicly available. Communication and collaboration with data set authors is strongly encouraged prior to use.

Data are available through download at the listed URLs.

There are no legal restrictions on access to the data. They reside in public domain and can be freely distributed. User must read and fully comprehend the metadata prior to use. Applications or inferences derived from the data should be carefully considered for accuracy.

User must read and fully comprehend the metadata prior to use. Applications or inferences derived from the data should be carefully considered for accuracy. While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty. Communication and collaboration with data set authors is strongly encouraged.

Cite data as: NMFS/AFSC/MML/Alaska Ecosystem Program (2021). Counts of Alaska Steller sea lion adult and juvenile (non-pup) conducted on rookeries and haul-outs in Alaska Aleutian Islands, Bering Sea, and others from 1904-01-01 to 2019-07-03 (NCEI Accession 0128190). NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.7289/v54f1np1. Accessed [date].

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Metadata are subject to revision at any time and information within the metadata record should not be cited without author consent. While every effort has been made to ensure that these data are accurate and reliable within the limits of the current state of the art, NOAA cannot assume liability for any damages caused by any errors or omissions in the data, nor as a result of the failure of the data to function on a particular system. NOAA makes no warranty, expressed or implied, nor does the fact of distribution constitute such a warranty.

Data table output as a .csv file from a SQL database.

STELLER SEA LION NON-PUP COUNT DATABASE

Last Update: June 10, 2021

The file "SSLnonpupcounts2019.csv" contains counts from Alaska of non-pup (adult and juvenile) Steller sea lions in the NMML database. The counts were made between 1904 and 2019. This file includes counts obtained during breeding season aerial surveys, as well as counts obtained during winter aerial surveys, boat surveys, cliff counts, and other miscellaneous counts.

The non-pup count data file (SSLnonpupcounts2019.csv) is in ASCII text format and fields are comma-delimited (.csv).

There are several issues with the data that users need to be aware of before using this database.

1. This database is continually being updated and modified. Users should check for the date the database was last modified.

2. This data set includes counts from all times year, some of which may not be appropriate for particular analyses. The number of sea lions at a given site is extremely seasonally dependent. Comparison of counts from November in one year and from July in another year is likely to produce confounded results. Population trend analyses typically are performed using data only from the breeding season June and July.

3. The most precise counts, and thus the counts preferred for population trend analyses, are aerial survey counts made from photographs. Counts made from skiffs or ships may be very accurate for small numbers of sea lions but imprecise for large groups. Visual estimates made from the air are best used as qualitative not quantitative data.

4. In general, this database includes counts of non-pup (adult and juvenile) Steller sea lions. This means that counts made during the breeding season (June and July) do not include newborn pups. After pups undergo their first molt in the fall or early winter, however, they are the same color as older sea lions and they are difficult or impossible to distinguish from juveniles. For this reason, counts made outside of the breeding season do include pups of the year that are 4 to 12 months old.

5. A zero in the COUNT field means the site was surveyed and no sea lions were present. If a site was not surveyed in a given year it is not included in the database; there are no records with the COUNT field blank.

6. Throughout the database "99" indicates that a day, month, platform, or source is unknown.

7. There are blanks in the COMMENT field. This may cause problems when end users import the ASCII text file into their preferred software format.

8. Site names are not consistent throughout the database. Surveys prior to 1990 frequently combined separate haul-out sites on an island into a single count, whereas more recent surveys usually list sites separately (e.g., Agattu versus Agattu/Cape Sabak and Agattu/Gillon Point). Also, the NMML continues to refine the definition of individual sites and occasionally adds new sites.

Not applicable.

See discussion in http://www.afsc.noaa.gov/Publications/AFSC-TM/NOAA-TM-AFSC-251.pdf

Data are not automatically processed.

IT Security and Contingency Plan for the system establishes procedures and applies to the functions, operations, and resources necessary to recover and restore data as hosted in the Western Regional Support Center in Seattle, Washington, following a disruption.

The Marine Mammal Laboratory (MML) conducted aerial surveys to photograph and count Steller sea lion (Eumetopias jubatus) non-pups (adults and juveniles ≥1 years old) on known terrestrial rookery and haulout sites in Alaska in June-July 2019 (Sweeney et al. 2019). On odd years, MML focuses their survey effort on the Gulf of Alaska (Southeast Alaska towards the western Gulf of Alaska) portion of the Steller sea lion range in Alaska. The occupied aircraft survey team conducted their survey from 24 June to 4 July from southeast Alaska (Dixon Entrance, 132°W) through the western Gulf of Alaska (Sanak Islands, 163°W). On even years, MML focuses their survey effort in the Aleutian Islands (from the western through the eastern Aleutian Islands regions), and sometimes into the western Gulf of Alaska region if not surveyed the previous year.

The ship-based survey team on board the R/V Tiĝlâx did not conduct visual counts or collect aerial imagery using an unoccupied aircraft system (UAS or drone) during the cruise from 20 June to 2 July. The survey team did travel the Aleutian Islands between Adak Island (176°W) and Attu Island (172°E) focusing on other research priorities.

No surveys were conducted in 2020 due to global COVID-19 pandemic.

For surveys back to 2008, see discussions in Fritz et al. (2013), Fritz et al. (2016), Sweeney et al. (2016), Sweeney et al. (2017), and Sweeney et al. (2018).