Salmon age, sex, and length data from Bristol Bay region of Alaska, 2010-2015

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 Bristol Bay region of Alaska. 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. 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 the original data files and an R script that reformats the original data files into a single dataset, 'bristol_bay_full.csv'.年龄、性别与体长数据可提供种群动态相关信息，用以阐释种群趋势的发生与变化规律。此类数据能够帮助研究人员估算种群增长率、年龄级分布以及种群统计特征。明晰种群统计特征、增长率与变化趋势，对于需要开展种群评估以支撑管理决策的渔业管理者而言尤为重要。因此，此类数据在阿拉斯加鲑鱼渔业这类高价值渔业中尤为关键。本数据集涵盖了阿拉斯加布里斯托尔湾区域内，基于商业性与自给性鲑鱼捕捞年度采样及相关研究项目所收集的年龄、性别与体长数据。年龄估算通过观察鱼鳞或骨质结构（例如耳石（otoliths）——耳部骨骼）完成。鱼鳞通常取自鱼体侧线以上的左侧区域。随后将鱼鳞或骨质结构粘贴于涂胶卡片上，并压覆于醋酸纤维膜以获取印痕。通过计数淡水与海水生长环（即年轮）的数量，以估算鱼类的年龄（以年为单位）。鱼类性别可通过观察外部形态（例如头部与腹部形态）或内部生殖器官进行判定。体长以毫米为单位进行测量，通常测量范围为眼部中点至尾叉处。本数据包包含原始数据文件，以及一段可将原始数据文件整合为单一数据集'bristol_bay_full.csv'的R脚本。