Surveys carried out to investigate the distribution and abundance of juvenile
mackerel. Two surveys per year in March and December. Station, catch, length
(all species) and biological data (selected species) are collect using
research vessels.
The standard bottom trawl used on these surveys was a modified Portuguese
High-headline Trawl fitted with 14” rubber bobbins on the groundrope and a
bunt tickler chain. The codend was fitted with a small-mesh liner (nominal
diagonal stretched mesh 20 mm).
The standard haul duration was 60 min and trawling was restricted to daylight
hours. Fixed station positions were used and for analytical purposes
