Salmon age, sex, and length data from Upper Cook Inlet, Alaska, 1967-2016

• Main Author: Alaska Department of Fish and Game, Division of Commercial Fisheries, Central Region
• Format: Dataset
• Language: unknown
• Published: Knowledge Network for Biocomplexity 2018
• Subjects: age, sex, length; Oncorhynchus Oncorhynchus tshawytscha; Oncorhynchus Oncorhynchus keta; Oncorhynchus Oncorhynchus kisutch; Oncorhynchus Oncorhynchus gorbuscha; Oncorhynchus Oncorhynchus nerka; Oncorhynchus tshawytscha; Oncorhynchus keta; Oncorhynchus kisutch; Oncorhynchus gorbuscha; Oncorhynchus nerka; Sockeye; Keta; Byers; Judd; Shell Lake; Byers Lake; Hewitt Lake; Judd Lake; Alaska
• Online Access: https://doi.org/10.5063/513WM9

Age, sex and length data provide population dynamics information that can indicate how populations trends occur and may be changing. These data can help researchers estimate population growth rates, age-class distribution and population demographics. Knowing population demographics, growth rates and trends is particularly valuable to fisheries managers who must perform population assessments to inform management decisions. These data are therefore particularly important in valuable fisheries like the salmon fisheries of Alaska. This dataset includes age, sex and length data compiled from annual sampling of commercial and subsistence salmon harvests and research projects in the Upper Cook Inlet. It includes data on five salmon species: chinook, chum, coho, pink and sockeye. Age estimates were made by examining scales or bony structures (e.g. otoliths - ear bones). Scales were removed from the side of the fish; usually the left side above the lateral line. Scales or bony structures were then mounted on gummed cards and pressed on acetate to make an impression. The number of freshwater and saltwater annuli (i.e. rings) was counted to estimate age in years. Age is recorded in European Notation, which is a method of recording both fresh and saltwater annuli. For example, for a fish that spent one year in freshwater and 3 years in saltwater, its age is recorded as 1.3. The total fish age is the sum of the first and second numbers, plus one to account for the time between deposition and emergence. Therefore the fish in this example is 5 years old. Fish sex was determined by either examining external morphology (eg. head and belly shape) or internal sex organ. Length was measured in millimeters, generally from mid-eye to the fork of the tail. This data package includes a .csv of ASL data (ASL_formatted_UpperCookInlet.csv) derived from an original metadata file (AGECOMP_METADATA_ALL.TXT), an original data file (MASTER_ASL_DATABASE_ARCHIVE_1967-2016.TXT), and a file containing location information (CookInletLocs.csv). The reformatting script (ASL_Formatting_CookInlet.R) draws pertinent columns from the data file and combines it with information from the metadata and locations files.