Vol. 53 - Alaska Resources Library and Information Services

strata (I and II) were created to give a qualitative sense of
interannual spatial and temporal changes in abundance. No statistical
contrasts were attempted since extensive sampling was done only in 1982
(Tables 3.2 and 3.3). In all other years, sample size for the two-month
period of May through June never exceeded 15 per stratum for areas that
exceed 12,000 km 2 (Fig. 3.12).
Large differences in density of larvae were noted both between
years and between strata I and II (Fig. 3.16 and Table 3.3). Most
samples were taken in the western NAS area in stratum I, which was
sampled every year from 1976 to 1982. The years of greatest abundance
were 1976-1977 when densities averaged 13,200 larvae/100 m 2 (Fig. 3.16;
densities in this stratum were very similar in both 1976 and 1977 and so
stations were combined to increase sample size). Average densities in
the years 1978-1982 were about 20 times lower in the range of 450-710
larvae/100 m 2 (Fig. 3.16, Table 3.3).
Stratum II was sampled only in the years 1980, 1981 and 1982.
Densities of larvae were highest in 1980 at 47,200 larvae/100 m 2 (only
three stations), and substantially less in 1981 at 1,780/100 m 2 . Comparison
of strata averages (Figure 3.16 and Table 3.3) shows that larvae
were always more abundant in stratum II than in I when both were sampled
in the same years (only two samples in stratum II, 1976 and 1977
combined). In 1982, average densities were 7,900/100 m 2 and 441/100 m 2
in strata II and I, respectively, and the few samples collected in 1980
indicate a 100-fold increase in average densities from west to east.
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