Vol. 53 - Alaska Resources Library and Information Services

circulating over the shelf.
Current and transport processes in the area
of major larval king and Tanner crab populations are the most important
to consider, and in this regard the North Aleutian Shelf along the 50 m
isobath and the St. George Basin in the vicinity of the 100 m isobath
are most important.
Hebard (1959) described currents moving to the
northwest through Unimak Pass, with a component then moving northeast
along the North Aleutian Shelf. Although the direction of the current
is highly variable and changes with tide, there is a net movement of
2.0- 5.5 cm/sec eastward and northward into Bristol Bay. Hebard was the
first to suggest that larvae of red king crab could be transported long
distances before metamorphosis, and thus recruitment of juveniles in one
area like Port Moller might be dependent on up-current populations near
Amak Island.
Kinder and Schumacher (1981b) summarized data for current
patterns in the southeastern Bering Sea and showed weak currents of 2-5
cm/sec along the NAS and 1-5 cm/sec moving northwest over the St. Geoge
Basin (Fig. 8.1).
They stress that instantaneous flow can be substantially
greater than these averages (up to 20X greater than the longterm
vector) and direction quite variable.
Cline et al. (1981) used
methane profiles to calculate current speeds of 7 cm/sec northeast along
the NAS and 5 cm/sec northwest over the St. George Basin, both values in
close agreement with current meter readings.
The importance of such information is to gauge the movement of crab
larvae in currents relative to origins and surface speeds of oil movement.
Such exercises have been done by Leendertse and Liu (1981) and
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