By R. Ted Cooney
Fisheries Research, Volume 18, Issues 1-2, Biological Interactions of Natural and Enhanced Stocks of Salmon, October 1993, Pages 77-87, ISSN 0165-7836, DOI: 10.1016/0165-7836(93)90041-5.

Present levels of feeding on zooplankton resources by wild and ocean-ranched juvenile Pacific salmon in Prince William Sound are estimated to be between 0.6 and 8.0% of the total `herbivore' production, and between 2.0 and 32.2% of the annual macrozooplankton production in the region. However, when annual fry losses to early ocean mortality are taken into account, the feeding demand associated with growth rates averaging 3-4% of the body weight per day fall to 0.8-3.2% of the total herbivore production and 3.0-10.0% of the macrozooplankton production. The results of this analysis suggest that present levels of salmon feeding have a minimal impact on zooplankton stocks in Prince William Sound. However, several key questions remain to be answered regarding the use of forage resources by wild and hatchery fry populations. It is important that answers to questions of resource partitioning be sought in light of evolving enhancement plans for salmon in this region.

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