Figure 19. (Top) Acoustic sections taken on the southern flank of Georges Bank from Stations 4 to 6 (most westerly) and Stations 8 to 12 (most easterly). Note the strong mid-depth acoustic layer running from the shelf break to the acoustically well-mixed zone. (Bottom) Acoustic sections taken further to the east running from Stations 13 to 16 (partially hidden) and from 16 to 20. Again note the strong mid-depth layer which runs about a third of the way towards the crest of the Bank before it intersects the well-mixed zone. Also present at the shelf break was a large very dense aggregation of very strong acoustic scatterers. We postulate that this was a substantial gadoid fish school.