AFSC/NMML/CCEP: Northern fur seal demography at San Miguel Island, California, 1974 - 2014

The National Marine Mammal Laboratories' California Current Ecosystem Program (AFSC/NOAA) initiated a long-term marking program of northern fur seals (Callorhinus ursinus) at San Miguel Island, California in 1975. A sample of up to 300 pups has been tagged in the foreflippers with various types and colors of tags each year between 1975 and the present. Resighting surveys for marked animals are conducted annually at summer breeding sites. Resightings are also obtained from the public when animals are observed on beaches or in fisheries. The data are used in mark-recapture models to estimate the age and sex specific vital parameters of the population and to describe age and sex specific reproductive behavior and seasonal movements of animals throughout their lives.

Estimates of age- and sex-specific survival and natality are used in population models to assess the status and describe trends of the northern fur seal population. Data are also used to describe life history traits such as age at first reproduction, dispersal patterns, and lifetime reproductive patterns.

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Cite data as: Orr, A. J., DeLong, R. L., Laake, J. L., Melin, S. R. 2016. Northern fur seal demography studies at San Miguel Island, California conducted from 1975-10-07 to 2014-09-26 (NCEI Accession 0141240). Version 1.1. NOAA National Centers for Environmental Information. Dataset.

Tables include information about individuals during initial Capture and after Resighing(s). See "Child Items" for more detailed information.

The user is responsible for the results of any application of this data for other than its intended purpose. NOAA denies liability if the data are misused. Applications or inferences derived from the data should be carefully considered for accuracy. Whereas 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 dataset is archived with the NOAA National Centers for Environmental Information (NCEI). 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. Communication and collaboration with dataset authors is strongly encouraged prior to use.

The dataset is available for download via the NCEI Ocean Archive System at http://accession.nodc.noaa.gov/0141240.

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. 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.

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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. Whereas 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.

Microsoft Access database with custom entry and editing software and code.

Contact Data Steward for specific information about inconsistencies in the data.

In the field, data were entered into a Microsoft Excel datasheet in a computer tablet that contained code to flag for tag numbers that did not exist, that had not been seen for more than three years, and if they were identified on the wrong side. Additionally, entries were flagged if the sex of the animal was mis-identified. Each evening, data were quality controlled by filling in fields that were not completed in the field, flagged entries were checked to determine if they were valid, error codes were addressed by comments, and duplicates were removed. Weekly or more frequently, the field supervisor placed all the individual files into a Master file. Data were rechecked before uploaded into database.

Data 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.

Each fall, a sample of up to 300, 3- to 4-month-old northern fur seal pups were marked using flipper tags. Rookery and haulout sites on San Miguel Island, CA were surveyed several times each week throughout the breeding season from late May to mid August for marked individuals. Surveys were opportunistically conducted at the Farallon Islands during the summer and fall. Individual's tag number, age-sex class and reproductive status were recorded. Resights were made using binoculars, spotting scope, or (digital) camera. Data were entered into a computer tablet using Microsoft Excel. The Excel spreadsheet contained code that flagged entries of tags that did not exist, flipper tags that have not been seen in over three years, mis-assigned flipper side tag was on, and mis-identified sex. Data were checked and compiled in master database. Duplicates were removed.