Vol. 53 - Alaska Resources Library and Information Services

into strata of the outer shelf domain (strata 5 and 8) during May and
June.
The cross-shelf increase of ten-fold in density is shown in
Figure 7.6 for the years 1976-1981; only data of 1980 deviated from the
trend of high middle shelf density (stratum 1) to low outer shelf and
shelf break densities (strata 2 and 3).
Stratum 1 mean densities ranged
from 1148 to 7566 larvae/100 m 2 (1980 low and 1978 high), compared to
stratum 2 densities of 649 to 1364 (1979 low and 1980 high).
General
scarcity in stratum 3 is illustrated by mean densities of 147 to 858
larvae/100 m 2 (1981 low and 1980 high).
7.2.3 Vertical Distribution
Vertical depth distribution of Paguridae larvae was studied by analysis
of MOCNESS samples from PROBES 1980 and 1981 (Fig. 7.7).
Pagurid
larvae were occasionally found down to 120-300 m but were primarily concentrated
within 0-80 m. Unlike the homogeneous distribution found
among the shrimp taxa, pagurids preferred the upper depth intervals with
44-47% in the upper 20 m, 71-76% in the upper 40 m, 84-89% in the upper
60 m, 95-96% in the upper 80 m, and 4-5% below 80 m. A diel comparison
of vertical depth distributions is given in Figure 7.8 for light (local
mean time (LMT) = 07:00 - 19:59) versus dark (LMT = 20:00 - 06:59) at
stations