A THEORETICAL EVALUATION OF THE CARRYING-CAPACITY OF PRINCE-WILLIAM-SOUND, ALASKA, FOR JUVENILE PACIFIC SALMON

Present levels of feeding on zooplankton resources by wild and ocean-r anched juvenile Pacific salmon in Prince William Sound are estimated t o be between 0.6 and 8.0% of the total 'herbivore' production, and bet ween 2.0 and 32.2% of the annual macrozooplankton production in the re gion. However, when annual fry losses to early ocean mortality are tak en into account, the feeding demand associated with growth rates avera ging 3-4% of the body weight per day fall to 0.8-3.2% of the total her bivore production and 3.0-10.0% of the macrozooplankton production. Th e results of this analysis suggest that present levels of salmon feedi ng have a minimal impact on zooplankton stocks in Prince William Sound . However, several key questions remain to be answered regarding the u se of forage resources by wild and hatchery fry populations. It is imp ortant that answers to questions of resource partitioning be sought in light of evolving enhancement plans for salmon in this region.