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Silver salmon experiment--1951 brood year
In the fall of 1951, experiments with silver salmon eggs
and fingerlings were conducted following the pattern used with
the 1949 brood year chinook salmon.
The silver salmon experiment was undertaken to provide
additional information on the effect of dilute concentrations
of the effluent water upon the fresh-water stage of one of the
important commercial salmon inhabiting the Columbia River
drainage.
The use of silver salmon for such experiments has
certain advantages over Chinook salmon,
have a longer fresh-water life,
for chinooks.
for the silver salmon
18+ months as compared to 6+
Furthermore, silver salmon have a shorter life
span, normally returning to spawn and die at the end of their
third year rather than the fourth as in the case of chinook
salmon.
The expectancy of return to the home stream is higher
for silver salmon, being about one per cent.
During the fall and winter of 1953-1954 five precocious
males,
"jacks," of each mark returned to the University of
Washington ponds.
Also some of this lot have been caught and
currently are being caught in the sport fishery.
The return
of this lot as mature spawning fish is expected during the
late
fall months of 1954.