Vol. 53 - Alaska Resources Library and Information Services

larvae. A computer program was used to generate listings of all MOCNESS
stations where larvae of a particular taxon were found.
For each depth
interval (0-20, 20-40, 40-60, 60-80, and >80 m) at each station, the
estimated abundance of larvae (number/1000 m 3 ), the number of larvae
actually counted for the estimate, and the size of the sub-sample providing
this count were listed.
Stations with estimates of larval abundance
based on too few specimens and/or on very small sub-samples were
not considered.
Although no strict criteria could be developed for making
this decision, it was generally not difficult to decide by inspection
whether the data were sufficient for adequately describing a vertical
distribution pattern.
For each station with sufficient data, the
vertical distribution of larvae was determined by calculating the proportion
of all larvae collected at each depth interval.
This was done for
each year of MOCNESS samples (1980 and 1981), and, sometimes, for individual
larval stages.
For some taxa, diurnal patterns were also examined.
2.8 Geographic Division of the Study Area
The study area was divided into twelve sub-areas, or strata (Fig.
2.21), for estimating mean larval abundance. The divisions were based
on regional hydrographic structure, faunal distribution patterns and the
availability of sampling data.
A breakdown of the southeastern Bering
Sea into strata facilitated comparisons of timing and abundance of certain
taxa between areas and years. This approach worked best with
Tanner crab and pandalid shrimp larvae, but also facilitated a summary
of general larval distributions for taxa that were less common or were
poorly sampled, such as king crab and Korean hair crab.
Estimates of
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