Michigan Department of Natural Resources
Research and Development Report No. 177
Institute for Fisheries Research Report No. 1755, 1969
Straying and Reproduction of Coho Salmon, Oncorhynchus kisutch,
Planted in a Lake Superior Tributary
James W. Peck
Introduction.-Adult coho salmon, Oncorhynchus kisutch, planted as smolts in a Lake Superior tributary, strayed into many other tributaries of the lake and reproduced successfully (Fig. 1 and Appendix A). Population estimates of young-of-the-year coho salmon in five of these streams showed that this reproduction was substantial.
Beal (1955) and West (1965) demonstrated that coho salmon which spent their entire life in fresh water can produce young if the sex products are removed and the eggs fertilized and incubated in a hatchery. However, to my knowledge there has been no documented evidence of reproduction in a natural environment by coho salmon which spend their entire life in fresh water. Straying and natural reproduction of coho salmon in Lake Superior tributaries of Michigan during 1967-68 and their management implications are described below.