Herring larvae surveys in the North Sea and adjacent waters, 1977/78

The results of the 11th International Survey of Herring Larvae in the North Sea and Adjacent Waters, which was carried out during 1977/78, are presented. They indicate a marked increase in larval production in both the northwestern and central North Sea compared with the previous two years. Some increase was also apparent in the Buchan area and in the southern North Sea/eastern Channel, although overall in these latter areas production was still at a relatively very low level. The spawning stock size of herring in the northwestern and central North Sea,as estimated from sub-area regressions of larval abundance on spawning stock size is 136 733 tons. It is likely that in addition a further 25 000 tons of herring spawned in the southern North Sea/eastern Channel. The catches of herring larvae taken by different countries were compared. It was found that there was no evidence of a significant difference in the catches of the critical< 10 mm size category.