A preliminary evaluation of the potential use of pelagic survey data in setting the horse mackerel PUCL

The existing population model for the horse-mackerel resource is extended to take commercial catch-at-length information from the mid-water trawl fishery and demersal surveys into account to allow the estimation of recruitment variations, which are correlated with the results for horse-mackerel abundance (considered to primarily reflect recruits) from the November pelagic surveys. Correlation is better with results for the West coast only from these surveys, rather than with those for the assessment area as a whole. At this stage the conclusion is either that these November survey estimates are (for whatever reason) a relatively weak predictor of incoming horse-mackerel recruitment strength, or that there are problems with the modelling of the demersal/midwater data which require further attention