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The Effect of Juvenile Rearing Density on Adult Returns of Summer Steelhead
Author(s) -
Tipping Jack M.,
Byrne James B.,
Hillson Todd D.
Publication year - 2004
Publication title -
north american journal of aquaculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 41
eISSN - 1548-8454
pISSN - 1522-2055
DOI - 10.1577/a04-010.1
Subject(s) - juvenile , biology , hatchery , zoology , fish <actinopterygii> , fishery , fish hatchery , rainbow trout , significant difference , oncorhynchus , aquaculture , fish farming , ecology , mathematics , statistics
Juvenile steelhead Oncorhynchus mykiss were reared at two hatcheries in an attempt to determine the influence of loading (kg · L −1 · min −1 ) and density (kg/m 3 ) on adult survival. At one hatchery in which fish were reared and released from raceways for 3 years, there was no significant difference in recovery rates of fish reared at levels 20% below normal loadings and densities compared with those reared at 20% above normal loadings and densities. At a second hatchery in which fish were reared in ponds for 3 years before release, flows were adjusted so that loadings were similar but densities differed; a significant decrease was observed in returns of test fish when loading was 2.1 kg · L −1 · min −1 and density was 5.8 kg/m 3 , and returns greatly decreased when test fish loading was 2.3 kg · L −1 · min −1 and density was 6.3 kg/m 3 .