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Vol. 53 - Alaska Resources Library and Information Services

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The distribution patterns for C. bairdi larvae reflect the general<br />

pattern anticipated on the basis of the adult spawning populations.<br />

Larvae were abundant over the St. George Basin, particularly over shelf<br />

depths shallower than 150 m. Larvae were also abundant near the <strong>Alaska</strong><br />

Peninsula, though the sampling effort in this region was comparatively<br />

low in most years.<br />

Analysis of data on estimated abundance of larvae in<br />

various sampling strata indicated that, over most of the area in this<br />

study, large interannual fluctuations in larval abundance of this<br />

species did not occur. Furthermore, in areas where adults of C. bairdi<br />

dominate, no statistically significant variations in larval year-class<br />

strength were observed.<br />

The charted distribution patterns of C. opilio larvae do not correspond<br />

closely to the adult populations. The abundance of benthic C.<br />

opilio between 70 <strong>and</strong> 100 m depths over the middle shelf, an area with<br />

weak net flows (Kinder <strong>and</strong> Schumacher 1981), suggests that this is where<br />

most larvae of this species should be found.<br />

Yet in 1977, 1978 <strong>and</strong><br />

1979, an abundance of larvae was found over portions of the St. George<br />

Basin (Fig. 4.11 shows the data for 1978 only).<br />

This pattern appears to<br />

result from three factors.<br />

First, sampling effort in years of abundant<br />

C. opilio larvae was more concentrated over the outer shelf (especially<br />

1977 <strong>and</strong> 1979). Second, the most extensive sampling of the middle shelf<br />

was conducted in two years (1980, 1981) of very low larval abundance of<br />

C. opilio. Finally, the most extensive sampling of an abundant yearclass<br />

of C. opilio was conducted in a year (1978) in which substantial<br />

wind-driven offshore transport occurred in April <strong>and</strong> early May (Incze<br />

634

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