Figure 2. Bivariate plots of δ¹³C vs. δ¹⁵N (top) and δ¹³C vs. δ³⁴S (bottom) values and histograms showing separation of δ¹³C (left) and δ³⁴S (right) values for salmon from different regions.

Comparative salmon data from modern scales²⁹,³⁰,³¹ as well as European⁵⁰,⁵¹,⁵² and North American⁵³ archaeological bone are denoted by an asterisk. Modern scale δ¹³C data has been adjusted by +1.25‰ to account for historical changes in environmental δ¹³C⁵⁹,⁶⁰. Data points for modern smolt (n = 442) and adult (n = 1866) salmon scales are average values for separate sample populations (including between 21 and 249 individual fish) in Europe, Greenland, and North America.