By W. W. Crozier, G. J. A. Kennedy
Fisheries Research, Volume 59, Issues 1-2, 30 December 2002, Pages 209-215, ISSN 0165-7836, DOI: 10.1016/S0165-7836(01)00402-7.

Migrating wild salmon smolts on the R. Bush, Northern Ireland, are tagged with coded wire tags (CWTs), as part of a study of salmon marine survival. We report the results of a comprehensive comparison of the effects of tagging on wild smolt survival, made possible by the total trapping facilities on the river, which allows simultaneous assessment of returns to the river of untagged wild fish. Analysis of one sea winter (grilse) returns to fresh water of tagged and untagged wild salmon over a 13-year period indicated that the tagged groups displayed significantly poorer return rates in each year of the study and overall (P