Data collection and scale processing
The literature was reviewed for published SI data of sockeye salmon scales. Johnson and Schindler (2012) reported on SI data for eight stocks distributed in Bristol Bay with time series spanning over four decades of scales collected every three years. Satterfield and Finney (2002) reported on a 30-year time series with yearly resolution for a stock located on Kodiak Island in SW Alaska, and Espinasse et al. (2018) reported on SI data for the Rivers Inlet stock (BC coast) which covered more than 50 years with irregular sampling resolution. In addition, we accessed archived scales for two major stocks in the Kamchatka Peninsula (Ozernaya and Kamchatka) (Bugaev et al., 2008), for two stocks of the Columbia River (Okanagan and Wenatchee), for two stocks in SE Alaska (Chilkoot and Chilkat) and for one additional stock on Kodiak Island. The stock locations can be seen in Figure 1 and the details of the time series resolution are provided in Table 1.