Table 1. Frequency (% within parentheses) of use of different tag types to study the life stages of anadromous salmonids in the marine environment for studies focusing on survival (i.e. those focusing on only survival and both on survival and behaviour).

	Tag type
Life stage	Acoustic	Radio	Data Logger	PIT	CWT	External	Biological	Row Total
Out-migration (juveniles)	23 (63.9/42.6)	3 (20/5.6)	0 (0/0)	7 (53.8/13)	10 (25.6/18.5)	11 (19.3/20.4)	0 (0/0)	54 (NA/100)
Out-migratin (juveniles) to open ocean	2 (5.6/20)	0 (0/0)	0 (0/0)	0 (0/0)	2 (5.1/20)	6 (10.5/60)	0 (0/0)	10 (NA/100)
Out-migration (kelts)	3 (8.3/42.9)	0 (0/0)	1 (100/14.3)	1 (7.7/14.3)	0 (0/0)	2 (3.5/28.6)	0 (0/0)	7 (NA/100)
Return migration	4 (11.1/15.4)	11 (73.3/42.3)	0 (0/0)	0 (0/0)	2 (5.1/7.7)	9 (15.8/34.6)	0 (0/0)	26 (NA/100)
Open-ocean	0 (0/0)	0 (0/0)	0 (0/0)	0 (0/0)	1 (2.6/33.3)	2 (3.5/66.7)	0 (0/0)	3 (NA/100)
Open-ocean to return migration	1 (2.8/100)	0 (0/0)	0 (0/0)	0 (0/0)	0 (0/0)	0 (0/0)	0 (0/0)	1 (NA/100)
Entire life cycle (juvenile-return adult)	3 (8.3/4.9)	1 (6.7/1.6)	0 (0/0)	5 (38.5/8.2)	24 (61.5/39.3)	27 (47.4/44.3)	1 (100/1.6)	61 (NA/100)
Column Total	36 (100/NA)	15 (100/NA)	1 (100/NA)	13 (100/NA)	39 (100/NA)	57 (100/NA)	1 (100/NA)	162 (100/100)

The first % value within parentheses shows the relative frequency of use of a given tag type across life stages. The second % value shows the relative frequency of use of different tag types to study a particular life stage. The total frequency of tag use (n = 342) exceeds that of reviewed papers (n = 207) because many studies encompassed more than one life stage. The category “Biological” includes otoliths and scales, whereas the category “External” includes Carlin, cinch, Floy, Petersen disk tags and external markings.