New Brunswick, Maine, St. Stephen, Calais, St. Croix River, Milltown Dam, Salmon, Smolt, Tagging, Smolt Release, Tag Returns, Grand Falls, Woodland 

"In 1981, 1982, and 1983, approximately 7,000 smolts from Green Lake hatchery were fitted with small Carlin tags and released above each of the three mainstem dams on the St. Croix River. The object was to evaluate downstream mortality at the Woodland and Grand Falls dams. The Milltown dam has lower installed power generation capacity than the upstream sites, thus it spills a higher proportion of the spring flow and so is expected to cause lower smolt mortality than the upstream sites (a separate study to evaluate the Milltown site is now underway).

Smolt mortality at the upriver dams can be estimated by tag returns from the angling and commercial fisheries and from the Milltown fishway trap. Total tag returns to date are 111 from 59, 719 tagged smolts (0.19%). Details of release sites and year of stocking are given in the accompanying table. Further details on tag returns from the commercial fishery (there were no angling returns) and estimates of effect of tag loss have been presented in the annual reports of the Milltown trap returns presented to the St. Croix River Biological Working Party."