Vol. 53 - Alaska Resources Library and Information Services

earlier discussion).
There was no diurnal periodicity to the depth distribution
pattern within the area of sampling, suggesting that the
peculiar distribution may have been the result of sampling at the time
of hatchout. Although the results (Figure 4.7) suggest a homogeneous
distribution, the large standard deviations show that, in fact, the
vertical distribution was highly variable from one sample to the next.
The vertical pattern could have resulted from 1) a hatchout which was
locally (at least within the advective area of sampling) quite synchronous,
and/or 2) a relatively slow upward movement of newly molted
zoeae, so that dense patches were found at various depths within the
area.
There is insufficient information in the existing data to further
evaluate these findings, except to point out that the distribution 1)
was not common, and 2) was not the result of unusual vertical water column
structure, as evidenced by other variables.
Hydrographic structure
and the distribution of nutrients, chlorophyll and the remainder of the
zooplankton community all showed normal vertical patterns at this location
(PROBES 1981 consecutive station numbers 2058, 2060, 2061, 2062,
2063).
The megalops larvae do not appear to have been quite as concentrated
in the upper 20 m as the zoeae, but they were still found primarily
in the upper 40 m during the period of sampling. Neuston samples collected
during night-time hours in July 1981 (Armstrong and Incze, unpubl.
data) sometimes contained impressive numbers of megalops larvae which
rivaled the estimates of abundance (per area of sea surface) obtained
from oblique tows taken within the area.
Although there are many
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