The Use of Acoustic Tags to Determine the Timing and Location of the Juvenile Coho Salmon Migration out of the Strait of Georgia, Canada

The migration of juvenile coho salmon Oncorhynchus kisutch out of the Strait of Georgia in 2006 was investigated by means of acoustic telemetry. During July and September, 173 juvenile coho salmon were caught in the strait with a purse seine, surgically implanted with acoustic tags, and released the same day. In 2006, approximately 19% of the fish tagged in July and 52% of those tagged in September left the Strait of Georgia. Most of these fish did so in October and November through Juan de Fuca Strait and not by a northward migration through Queen Charlotte Strait. This movement was several months later than that observed for coho salmon migrating out of Puget Sound. A small number of coho salmon that moved out of the Strait of Georgia migrated south to areas off the coast of Washington and Oregon. The documentation of a movement out of the Strait of Georgia late in the year was important, as it shows that population changes of the juvenile coho salmon that enter the strait during spring and summer are a consequence of ecosystem-related effects within the strait.