Vol. 53 - Alaska Resources Library and Information Services

strongly disagree with this hypothesis and believe that any significant
reduction or a complete loss of a year-class could adversely
affect the fishery 7-8 years later. As noted in Section 3.0, greater
than 60% of any year's fishery may be comprised of new recruits
from a single year-class.
Otto et al. (1982) summarized population
estimates for red king crab over the last 10 years and noted a significant
decline in pre-recruit males in 1980 through 1982.
Both
the 1981 groundfish survey and commercial fishery have verified the
existence of very weak year-classes, and the fishery in this and
next year will be very poor (Section 3.0).
Such reduction in commercial
stocks probably results from poor survival during early
life-history stages of larvae and new instars that is caused by
poorly understood sources of natural mortality (exceptionally cold
years of 1975-76 and excessive predatory pressures on small benthic
instars are hypotheszied to be contributory causes; Section 3.0).
Large-scale mortality of larvae caused by oil pollution could eventually
be just as critical to the fishery as are unusually high
losses due to natural causes.
This would be particularly true of
C. opilio Tanner crab because of the apparently sporadic recruitment
success of this species under natural conditions (see Section
4.0; Incze 1983; Somerton 1981). Obviously, consecutive years of
oil pollution or scenarios described in Item 4 of this subsection
where pelagic larvae of one year are killed and benthic eggs for
the following year's hatch simultaneously poisoned, would cause
even greater harm to the fishery.
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