Summary of Pacific Salmon Escapement Goals in Alaska with a Review of Escapements from 2007 to 2015

This dataset is compiled from Tables 1-4 from the report "Summary of Pacific salmon escapement goals in Alaska with a review of escapements from 2007 to 2017." Escapement is defined as the number of mature salmon migrating from the marine environment to freshwater streams. Escapement data are the enumeration of these migrating fish as they pass upstream, and are a widely used index of spawning salmon abundance. These data are important for fisheries management, since most salmon harvest occurs in freshwater rivers during this migration. As a part of management of these salmon stocks, some Alaskan river systems are assigned escapement goals, which generally represent the number of salmon that need to be given the opportunity to spawn to ensure survival of the stock. Generally there are three common types of escapement goals. Biological Escapement Goals (BEGs) are defined in Alaska fishery regulations 5 AAC 39.222(f) as "the escapement that provides the greatest potential for maximum sustained yield." Sustainable Escapement Goals (SEGs) are defined in the same section as "a level of escapement, indicated by an index or an escapement estimate, that is known to provide for sustained yield over a 5 to 10 year period, used in situations where a BEG cannot be estimated or managed for." Optimal Escapement Goals (OEGs) are defined as "a specific management objective for salmon escapement that considers biological and allocative factors and may differ from the SEG or BEG."

本数据集源自报告《阿拉斯加太平洋鲑鱼洄游产卵目标综述及2007至2017年洄游种群复盘》中的表1至表4。洄游产卵种群数量（Escapement）指成熟鲑鱼从海洋洄游至淡水溪流的总个体数。洄游产卵种群数量数据是对这些洄游鱼类溯河而上时的计数统计结果，是衡量产卵鲑鱼种群丰度的通用指标。由于多数鲑鱼捕捞活动均发生在该洄游阶段的淡水河道中，此类数据对渔业管理具有重要价值。作为鲑鱼种群管理的组成部分，部分阿拉斯加河流流域被划定了洄游产卵目标值，该值通常指需确保获得产卵机会以维持种群存续的鲑鱼数量。当前主流的洄游产卵目标值共三类：生物学洄游产卵目标值（Biological Escapement Goals, BEGs）在阿拉斯加渔业条例5 AAC 39.222(f)中被定义为"能为获取最大持续产量提供最大潜力的洄游产卵种群数量"；可持续洄游产卵目标值（Sustainable Escapement Goals, SEGs）在同一条例条款中被定义为"通过指标或洄游产卵种群数量估算值确定、可在5至10年周期内维持产量的种群数量水平，适用于无法估算或管理生物学洄游产卵目标值的场景"；最优洄游产卵目标值（Optimal Escapement Goals, OEGs）则被定义为"兼顾生物学与分配因素的鲑鱼洄游产卵专属管理目标，其数值可能与可持续洄游产卵目标值或生物学洄游产卵目标值存在差异"。