Comparison of Sequential Coded Wire and Passive Integrated Transponder Tags for Assessing Overwinter Growth and Survival of Juvenile Coho Salmon

Abstract

Abstract Wild juvenile coho salmon Oncorhynchus kisutch in a natural stream were marked with either sequential coded wire (s-CW) tags or passive integrated transponder (PIT) tags to assess possible differences in growth and survival from fall to spring between fish tagged with the two types of tags. Survival, estimated from recovery of out-migrants, varied between years (25.4% in 1990–1991 and 42.1% in 1991–1992), but there was no difference in apparent survival between fish of the two tag groups in either year. Weight gain from fall until emigration from the stream the following spring also varied between years (0.021 and 0.028 g/d in 1990–1991 and 1991–1992, respectively; final weights: 4.55 g in 1990–1991 and 6.01 g in 1991–1992), but growth did not differ between tag groups. Differences in survival and growth were not detected in even the smallest size-class tagged (53–70 mm). We conclude that overwinter growth and survival estimates of coho salmon as small as about 2.8 g and 65 mm fork length would n...