FISHERIES_2020_JUL_SWG-PEL_49_presentation.pdf (129.94 kB)

Does the ratio of juvenile sardine : anchovy observed in the fishery and the recruit surveys correlate with that predicted by models?

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presentation
posted on 18.02.2021, 12:23 by Carryn de Moor, Doug Butterworth
Virtual presentation to the Small Pelagic Scientific Working Group, Cape Town, 14 July 2020: 6pp.
The ratios of juvenile sardine to anchovy observed in the fishery and in the recruit surveys are compared against those estimated by the anchovy assessment model. Assuming the model ratio of sardine:anchovy recruit numbers represents the ‘true’ ratio, it is found that almost no reliable inference can be made about the true ratio from that observed in the fishery, (possibly because the industry take steps to avoid areas with high juvenile sardine bycatch), but that some inference is possible from the ratio observed in the survey (though this has relatively high variance).

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Department of Mathematics and Applied Mathematics, University of Cape Town