INTERANNUAL VARIATIONS IN CONDITION INDEXES OF LARVAL NORWEGIAN SPRING-SPAWNING HERRING

The sea water temperature off the Norwegian coast was lower in 1994 th an in 1992 and 1993. RNA/DNA ratios of Norwegian spring spawning herri ng increased with increasing larval dry weight all years, except for l arvae sampled south of 62 degrees N in 1994. The RNA/DNA ratios indica ted that each year, only a small portion (less than or equal to 0.7%) of the larvae were starving. RNA/DNA ratios and temperature were negat ively correlated in 1992, but in other years no significant correlatio ns were found. Residuals of ln RNA v. In DNA and In Wv. L-s were poorl y correlated in all years, but residuals of ln RNA v. In DNA and In DN A v. ln W were negatively correlated in all years. Principal component analysis showed that the RNA/DNA ratio and DNA (% of weight) were cor related with different axes. Abundance data for herring at the early l arval and 0-group stages in 1992-1994 indicated higher mortality in 19 94 compared with the other years. The data do not indicate that averag e larval condition was poorer in 1994 than in other years. However, th e variability in larval condition was higher in 1994 than in other yea rs, and the condition of later larval stages was relatively lower in 1 994 than in other years. (C) 1997 The Fisheries Society of the British Isles.