POD! Fish abundance measurements and related parameters used in first POD Change Point and MAR analyses (nceas_data_one).

These data were provided by Fred Feyrer on 29 April 2008. The data are intended for the change point and MAR analyses. The first sheet has the data and the second sheet has the definitions for each variable. The data sheet has 110 columns representing variables and 40 rows representing years (1967-2006). Because there are so many variables, Fred added columns indicating which variable is associated with which analysis (on the definition sheet). There is a column for every variable we discussed during the 7-11 April meeting at NCEAS with the exception of prickly sculpin. Fred looked at the data from the Bay Study and the catches were low and sparse enough that he didn't feel the information was meaningful. Fred included a few extra variables for the measures of fish abundance. Initially we decided to use average catch per trawl for age-0 fish that were collected in the fall midwater trawl survey. However, using age-0 actually limits the number of years available for analysis because not all fish were measured for length in all years. Accordingly, Fred also included total catch per trawl, which is available for all years when the survey was conducted. Fred also included the CA Dept Fish and Game Abundance Indices (age-0 and total) for the same species as a comparison. Most of these are correlated because the gear samples age-0 fish best. The point is that using total catch per trawl will increase sample size and likely provides a result very similar to using age-0 catch per trawl. Keywords:本数据集由Fred Feyrer于2008年4月29日提供，旨在用于突变点（change point）分析与MAR分析。首个工作表包含原始数据集内容，第二个工作表则给出各变量的详细定义。数据工作表共包含110列（代表变量）与40行（对应1967年至2006年的年度数据）。由于变量数量较多，Fred在定义工作表中新增了标注列，用于指明各变量对应的分析组别。除棘绒杜父鱼（prickly sculpin）外，本数据集涵盖了2008年4月7日至11日于国家生态分析与综合中心（National Center for Ecological Analysis and Synthesis, NCEAS）召开的会议中讨论过的全部变量。Fred对海湾研究（Bay Study）的数据进行了检视，发现棘绒杜父鱼的渔获量极低且分布稀疏，因此认为其相关信息不具备统计学意义，故未将其纳入数据集。此外，Fred额外新增了若干鱼类丰度测度相关变量。团队最初拟定采用秋季中层拖网调查中采集的0龄鱼的单位拖网平均渔获量作为丰度指标，但使用0龄鱼数据会限制可用于分析的年份范围——因为并非所有调查年份均完成了全部鱼类的体长测量工作。为此，Fred同时新增了单位拖网总渔获量数据，该数据在所有开展拖网调查的年份中均可获取。此外，Fred还纳入了加利福尼亚州鱼类与野生动物部（CA Dept Fish and Game）针对同一物种的丰度指数数据（包含0龄鱼与总渔获量两类），用于对比分析。由于该采样渔具对0龄鱼的采样效果最佳，因此多数指数间存在较强相关性。核心结论为：采用单位拖网总渔获量可有效提升样本量，且其分析结果大概率与使用0龄鱼单位拖网渔获量的结果高度一致。 关键词：