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The importance of measuring biotic and abiotic factors in the lower egg pocket to predict coho salmon egg survival
Author(s) -
Meyer C. B.
Publication year - 2003
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1046/j.1095-8649.2003.00039.x
Subject(s) - biology , abiotic component , oncorhynchus , biotic component , hatching , sediment , ecology , zoology , fishery , fish <actinopterygii> , paleontology
Based on results from simulated redds of coho salmon Oncorhynchus kisutch , the amount of fine sediment <0·5 mm in the lower half of the egg pocket, rather than the entire egg pocket of the redd, was a strong predictor of egg survival to hatching ( r 2 = 0·62). The relationship was much stronger than observed in other studies, which typically ignore egg pocket structure. Abundance of a fish egg‐eating worm, Haplotaxis ichthyophagous , an oligochaete that may have been attracted to fine sediment and dead eggs in the egg pocket, was also associated with a decrease in egg survival. The worm, however, accounted for little of the variance in survival compared to fine sediment. Only 10% fine sediment (<0·5 mm) in the lower pocket was required to decrease survival from 100 to 5%. Other abiotic factors had weaker (gravel permeability) or non‐existent (dissolved oxygen) correlations with survival.