Title: A review of Namibian Cape horse mackerel (Trachurus capensis) stock assessment data and comparison of the existing age structured production model (ASPM) approach with an alternative approach using stock synthesis (SS).

Evaluation of stock assessment input data was carried out to identify possible errors with the data to facilitate improvement of the horse mackerel stock assessment. Major issues were identified with the recording and processing trawl duration data and some causes of the errors were identified. The identified errors could not be corrected as they required reference to the raw data sheets. Comparison of the Age-structured production model (ASPM) and Stock Synthesis to provide exposure to the practice model-based fisheries stock assessment and this goal was realised in relative terms. The two models provided divergent outputs in terms of derived quantities but followed similar trends for the larger part of the data time series.