Carcassman,

Best I recall, Canadian interceptions really took off beginning in the late 60s, early 70s, coinciding with greatly reduced returns to Puget Sound and WA coast, but not as bad as PS.

Rivrguy,

CWT came into wide use about 1972. Frank Haw's buddy up on Shaw Is. invented the machine to make the tags and inject them in smolts.

Sg