ORIGIN OF ADULT CHINOOK SALMON
IN THE ST. MARY'S RIVER


Frederick W. Aldinger III

School of Science and Natural Resources
Lake Superior State University
Sault Ste. Marie, MI 49783





Abstract. One hundred and eight four chinook salmon (Oncorhynchus tshawytsha) were
sampled from the St. Mary's River during fall, 1995. Vertebrae were removed from fish
lacking fin clips and viewed under ultraviolet light to determine the presence of
oxytetracycline (OTC). Presence of an OTC mark or a fin clip identified the chinook as
stocked by the Michigan Department of Natural Resources or the Sault Ste. Marie Ontario
Municipal Hatchery.  No mark at all would indicate the chinook was naturally
reproduced or an unmarked fish from another Ontario hatchery. Definitive determination
of natural chinook was not possible due to unmarked chinook from other Ontario
hatcheries migrating to the St. Mary's River instead of returning to their release sites to
spawn. Of the 184 chinook examined 98 (53.3%) were stocked by the Michigan
Department of Natural Resources, 36 (19.5%) were stocked by the Municipal Hatchery,
and 50 (27.2%) were natural or from other sources.







Selected References

Hesse,	J.A. 1994. Contribution ofhatchery and natural chinook salmon to the
eastern Lake Michigan fishery, 1992- 1993 . Master's Thesis. Michigan State
University, Lansing, MI.

Weber,	D.D. and G.J. Ridgway. 1962. The deposition of tetracycline drugs in
bones and scales of fish and its possible use for marking. The Progressive
Fish Culturist. October:150-154.