1. To determine the effect of extension length on the selectivity of a 110 mm diamond mesh cod-end rigged with a 90 mm square mesh panel using the twin trawl method.
2. To carry out underwater observations of the gear and fish reactions to it using the RCTV.
3. If no significant effect of extension length is found, the effect on selectivity of using double twine in the aft 100 meshes of the extension will be measured.
4. To measure, as time allows, the selectivity of a 110 mm diamond mesh cod-end with no square mesh panel using hooped small mesh covers. This rig will replace the 40 mm diamond mesh cod-end attached to the control net.
Robert J Kynoch (Fisheries Research Services Aberdeen Marine Laboratory)
Biology and fisheries
Description: 20-25 miles east of Peterhead codend selectivity trials took place.
No. of trials not noted
Description: 10 miles east of Peterhead observations were made using the RCTV.
No. of observations not noted.