The SCAA Assessment of SA hake Rebecca Rademeyer and Doug Butterworth The SCAA Assessment of SA hake Rebecca Rademeyer and Doug Butterworth . MARAM

The fishery in 2006 Low catch rates had the fishery hardly returning any profit Species disaggregated assessments pointed to a highly depleted M. paradoxus resource MSC certification required that resource returned to Bmsy

Key SCAA assessment model features Two species, treated as separate populations, but assessed within the same framework to take account of commercial size data that cannot be disaggregated by species. Furthermore assumptions required for prior to 1978 for which no species disaggregated data, including total catch data, are available. Sex-disaggregated Estimate growth curves internally, fitting to age-length information under the assumption of time-invariant length-at-age distributions Different selectivities on the WC and SC to reflect different age/ length structures

Data fitted Total catch for each fleet (species disaggregated externally – pre-1978 assumption; post-1978 analysis) CPUE: ICSEAF CPUE series (pre-1978, species-aggregated) GLM-standardised CPUE (1978-present, disaggregated by species and coast) Commercial catch-at-length by fleet (species and sex disaggregated information for the longline fleet only) Survey indices (4 series: WC summer, WC winter, SC spring, SC autumn; species disaggregated; since 2003 alternation of gear on the research vessel requires the use of calibration factors) Survey catch-at-length (4 series as above; species disaggregated; sex-disaggregated for some years) Age-length keys (species- and sex-disaggregated for some years only)

Commercial selectivity-at-length M. paradoxus M. capensis

Fit to CPUE data

Fit to survey data

Spawning biomass trajectory M. paradoxus

Spawning biomass trajectory M. capensis

Recruitment trajectories M. paradoxus M. capensis Note relatively poor recruitment over years around 2010

Projections under OMP-2014 . (Reference Case)

SCCA assessment – What next? Refine assessment to provide Operating Models for 2018 SA hake OMP revision process Use M(year, age) matrix from hake predation model