Forums / Proposed MRR Fields / Study type, Study Integrity

Study type, Study Integrity

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  • Richard Townsend
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    2 posts
    Registered:
    20 Jun 2012
    25 Jun 2014
    System-wide survival is often estimated using whatever PIT-tagged fish traveled through the area of interest, with the huge assumption that they are representative of all fish being investigated.   Estimates of survival will be biased if this assumption is not true, but who has the resources to query every organization of the appropriateness of using their releases to estimate survival, or wants to field all questions from multiple analysts in regards to releases 10 years earlier?  Assuming PTAGIS is to exist for awhile, and after the original managers have long retired and their study records have disappeared over time, there will be no way to confirm which PIT-tagged releases are the most appropriate.  With this in mind, I propose 2 fields that are currently used by the CWT (RMIS.org) database:

        1. "Study Type", values = ("production"; "experimental"; "both"; "other") , and
        2. "Study Integrity", values = ("normal", "other").

    Study type would go a long way towards removing those fish that were part of some experiment that may bias their ultimate survival (either higher or lower) through the system.  I’m not advocating detailed information be added, just some type of indication that to include a release labeled as "experimental" would not guarantee an unbiased estimate of what is to be measured.  If the region could agree on which fish are appropriate, there may be less confusion in the various analysis outcomes.

    Study integrity would be the appropriate flag on whether a normal survival estimate would be expected.  “Other” would be applied to studies that perhaps had a mishap during release, unforeseen circumstances in the process occurred (high winds, unusual high/low temperatures, etc.)-- something to indicate the presence of influence(s) on the release group so that it would not likely experience a “normal” survival process through the system.

    I know that the asking researchers to share specific information about what is being done in the study is impossible.  Multiple groups are already using everyone’s data to get survival estimates for the region.  I’m suggesting a “use with caution” label to go with the data, to be entered by the people who would know the best--the individual managers of the study.
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  • Dave Marvin
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    13 posts
    Registered:
    02 Nov 2012
    28 Jul 2014
    I agree with Rich's statement that "[s]ystem-wide survival is often estimated using whatever PIT-tagged fish traveled through the area of interest".  However, I don't think such estimates are acceptable; nor do I believe that the assumptions behind such estimates can be addressed, much less validated, with the "Study Type" and "Study Integrity" attributes that Rich has proposed.  While these attributes may have utility within the scope of data contained in the RMIS database to categorize the predominately direct releases of production groups of hatchery-reared Pacific salmon and steelhead, these study attributes would apply to only a portion of the diverse species and study groups in the PTAGIS dataset for which a "system survival" analysis would be appropriate.  This is especially true for salmon and steelhead smolts released in the Snake and Columbia rivers to address specific project passage and/or survival goals, and particularly those fish with a PIT tag as an adjunct or secondary mark.  While these PIT-tagged fish would not be candidates for inclusion in a system survival analysis, I'm sure they are considered to be "representative" by their respective projects, with "normal" (or "superlative" or "beyond reproach") "integrity".

    Rich's frustration in identifying "appropriate" data is understandable.  The ability, or potential, to re-purpose 25+ years of regional mark/recapture data is a tantalizing prospect.  It may be easier to first winnow out the data that are inappropriate to an analysis and then address the assumptions inherent in the remaining data groups.  For that reason, I'll propose a new "Project Identifier" attribute to link tag data with a persisted collection of each study's objectives, protocols, and documentation.  This context should make it easier to narrow the scope of potentially appropriate data for a secondary analysis of survival or other metric.

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  • Richard Townsend
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    2 posts
    Registered:
    20 Jun 2012
    05 Aug 2014 in reply to Dave.Marvin
    Historically, I've observed a reluctance of study owners to share all the details of their study.  Dave's suggested "Project Identifier" attribute is the ideal addition to the data base, and I heartily endorse it.  Given the region's trend the last few years towards making this information available, I would love to have this implemented in the next version. 

    The attributes I suggested are merely the initial steps toward this process, and are something I think would be more likely to be reported, due to their generic details.  Though I had only listed  a few categories, these could be increased to provide more detail, without being too specific.  In the end whether a detailed or generic study identifier attribute is added (or not) to the database will come down to the will of the funding agencies to require the information be added, or to the study owners to volunteer it.  As a data user, I just want the most information to better my analyses.
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