Sockeye salmon age measurements from scale data, Alaska, 2011-2017

This dataset contains digitized scale measurement data from sockeye salmon scales taken in Alaska. The locations where scales were sampled are the Copper River, Coghill River, Egegik River, and Hugh Smith Lake. Salmon scales are aged by examining growth annuli on the scale. Sockeye salmon typically spend one to two winters in fresh water, and one to three winters in the ocean prior to returning to freshwater to spawn. Growth during summer months is rapid, and increases the size of the scale by widely spaced circular rings (circuli). Slow growth during winter months leads to more narrowly spaced circuli. In this dataset, measurements are presented as the length (in millimeters) between each circuli. Accompanying these individual measurements is the established age of the fish (in European notation, where a 13 would be 1 year in fresh water and 3 in the ocean), the sex of the fish, and the length of the fish. Included in this dataset are the original excel files for each aged stock, an Rmarkdown document which reformats and merges these files, and a csv file of all of the data contained within the excel files. The included PDF document details the methods for measuring annuli more clearly.