SCRS_2018_134.pdf (3.55 MB)

Updated summary of conditioned operating models for Atlantic bluefin tuna

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posted on 01.04.2021, 12:36 by Tom Carruthers, Doug Butterworth
Bluefin tuna operating models were revised and refitted to data in order to: (1) account for a longer time period for which index data are available; (2) provide an improved interpretation of stock mixing data; (3) better represent assessment estimates of historical stock trends and (4) approximate uncertainties over the strength of past and future recruitment. A total of 36 reference case operating models for Atlantic bluefin tuna are described. The fits of these models to data are presented in this paper. The various operating models fitted similarly well to the indices and none appeared to warrant rejection from the reference set with the exception of OM #14. The fitted reference operating models span a reasonably wide range of estimates for stock status and productivity, which may render the third current abundance option unnecessary. The fishery-independent and CPUE indices currently proposed for use for generating future data to use an input to Candidate Management Procedures, which span younger and older life stages in both eastern and western areas, had acceptable fitting diagnostics.



Department of Mathematics and Applied Mathematics, University of Cape Town