Review of the Marine Recreational Information Program (2017) / Chapter Skim
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8 Plans for Maintaining Continuity
8 Plans for Maintaining Continuity
Pages 123-130
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From page 123... ...
The resulting estimates of catches differed from those produced by Marine Recreational Fisheries Statistics Survey (MRFSS) and created the need to link and calibrate previous information collected under MRFSS with the new information from the MRIP, to create a continuous time series of equivalent data.
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From page 124... ...
For example, calculation of season lengths or bag limits designed to maintain historical angler success or access will be sensitive to the input data. Existing control rules used for input management control may need to be reassessed in light of the adjusted time series of catch estimates by time or area.
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From page 125... ...
This is because the changes contemplated by this report will affect primarily the degree of offset between the two time series, which the calibration is designed to bridge. However, it is important that MRIP staff be cognizant of any changes in methodology that affect the determination of peak fishing effort periods, because all calibration methods currently contemplated involve the use of peak effort periods to calibrate MRFSS estimates to MRIP estimates.
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From page 126... ...
Both workshops clearly recognized that calibration was critical in allowing stock assessments to differentiate true changes in stock status from changes in the estimation procedures producing the data used in the assessments. Both workshops also identified several issues that affect the sampling error of the catch estimates, based on changes to the survey designs of both the MRFSS and MRIP over time.
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From page 127... ...
This estimator is more involved than the ratio estimators and is in some measure the reverse of the complex ratio estimator. It uses 2013 data to estimate and predict the distribution of morning, peak, and evening categories of catch/effort for 2013, based on characteristics of the catch or demographics from the APAIS.
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From page 128... ...
stock assessments, while not immune to differences, are the least sensitive to calibration issues because the assessment models can accommodate some imprecision in calibration through alternative catchability functions. Imprecise or biased calibration does affect the calculation of reference points related to unfished biomass, hence optimum harvest rates and control rules.
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From page 129... ...
These issues are not uniquely associated with the methodology for calibrating data series resulting from changed estimation methodologies, but imprecision in calibration will increase uncertainty in fisheries management. Future efforts to develop calibrated time series of recreational catches will be most useful if accompanied with advice on the implications of the calibration method to stock assessment and reference points for stock management.
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From page 130... ...
For simpler stock assessments, the calibration may be more influential. Recommendation: The MRIP should continue development of a statistically sound calibration methodology as improvements to the Access Point Angler Intercept Survey and Fishing Effort Survey methodologies are incorporated.
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