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Vol. 53 - Alaska Resources Library and Information Services

Vol. 53 - Alaska Resources Library and Information Services

Vol. 53 - Alaska Resources Library and Information Services

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ABSTRACT<br />

The goal of this study was to better define the relationship between<br />

larval distribution <strong>and</strong> juvenile recruitment of red king crab (Paralithodes<br />

camtschatica) in the Bristol Bay region. Cruises during April-<br />

May, June <strong>and</strong> September 1983 collected larvae with bongo net tows,<br />

<strong>and</strong> juveniles <strong>and</strong> adults with trynet trawls <strong>and</strong> rock dredge hauls.<br />

Ancillary physical <strong>and</strong> biological measurements were made <strong>and</strong> tested for<br />

correlations with the observed larval <strong>and</strong> juvenile distributions.<br />

The results of the larval sampling demonstrated a very weak 1983 cohort.<br />

Hatch apparently occurred during the last week of April <strong>and</strong> the first<br />

week of May, later than recorded in most years. The distribution of<br />

larval red king crab in Bristol Bay was characterized by a density<br />

maximum near the middle of the bay, <strong>and</strong> generally low density along the<br />

North Aleutian Shelf (NAS) as compared to earlier years. Larvae were<br />

not found in Togiak or Kvichak Bays. Vertically stratified samples gave<br />

strong evidence of diel vertical migration by red king crab larvae. The<br />

distribution of larval red king crab observed during 1983 is generally<br />

consistent with the concept of transport northeast along the North<br />

Aleutian Shelf <strong>and</strong> northwest in the upper part of Bristol Bay. It is<br />

not known whether longshore NAS currents may persist all the way into<br />

Kvichak Bay, but the occurrence of 1983 young-of-the-year crabs suggest<br />

this since no larvae were observed there. It is not clear whether<br />

the location of the larval density maximum was a result of offshore<br />

transport from the NAS or release by ovigerous females observed in the<br />

middle of Bristol Bay.<br />

The results of juvenile sampling demonstrated the presence of crabs<br />

younger than three years generally inshore of the 50 m isobath. Age O+<br />

crabs (1982 cohort) were found off Ports Moller <strong>and</strong> Heiden <strong>and</strong> in Togiak<br />

<strong>and</strong> Kvichak Bays, both during April-May <strong>and</strong> June. Young-of-the-year<br />

crabs (1983 cohort) were found off Ports Moller <strong>and</strong> Heiden <strong>and</strong> in<br />

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