7606

• UCREFRP Catalog Number: 7606
• Author: Negus, M. T., D. A. Belford and S. E. Colvin.
• Title: Long-term Retention of Fluorescent Pigment Marking of Chinook Salmon.
• USFW Year: 1990.
• USFW - Doc Type: St. Paul, MN.
• Copyright Material: NO

ABSTRACT
Chinook salmon (Oncorhynchus tsha~scha) of
approximately 50 mm total length were spray-marked in
spring 1984 with red fluorescent pigment. Spray-marked
fingerlings, along with an equal number of control
fingerlings, were fin-clipped and released into the French
River, a tributary to Lake Superior. Marked chinook salmon
were recaptured as age 2+ to 5+ spawning adult migrants.
Primary locations for pigment retention were the body side
and the transparent tissue near the eye. Eighty-eight
percent of the adult females and 63% of the males retained
at least one pigment granule. Spray-marking did not appear
to influence growth, but some increased mortality was
indicated, possibly due to the cumulative stress of spray-
marking and fin-clipping.

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