Pacific saury (Cololabis saira) has a 2‐year life span and age‐1 fish migrates from the central and western North Pacific to Japanese waters from summer to winter. To understand interannual abundance variability of Pacific saury in the North Pacific, we examined the extended Japanese standardized catch per unit effort (esCPUE) with generalized linear models (GLMs) during 1982–2018. Explanatory variables included proxies of total and non‐traditional fishing effort (Ettl and Ent) and environmental factors. Each environmental variable was averaged for years t ‐1 and t, corresponding to esCPUE in year t, as esCPUE represented two‐year classes. Ettl and Ent were averaged for years t ‐ 2 and t‐1, assuming fishing of year t affects biomass in year t + 1. We compared four GLMs with different explanatory variables: (a) environmental factors only, (b) fishing effort (without interactions) only, (c) environmental factors and fishing effort (without interactions) and (d) environmental factors and fishing effort (with interactions, i.e., time‐varying effects). Explanatory variables of the best GLM in terms of AICc included the following: Ent with different effects between 1982–2015 and 2016–2018, sea surface water temperature (SST) of the Kuroshio Recirculation Area (KRA) in winter, North Pacific Gyre Oscillation (NPGO) in winter, Southern Oscillation Index in winter, and the biomass of Japanese sardine. The NPGO, a proxy of zooplankton abundance, and KRA‐SST may affect the early growth and survival rates of Pacific saury. We hypothesized the abundance variability of Pacific saury was driven by environmental factors and fishing, the latter of which more adversely affected since 2016.

中文翻译：

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澄清环境因素和捕鱼对1982-2018年间北太平洋西部太平洋秋刀鱼（Cololabis saira）的丰度变化的影响

太平洋秋刀鱼（Collolabis saira）的寿命为2年，从夏季到冬季，年龄为1岁的鱼从北太平洋中部和西部迁移到日本水域。为了了解北太平洋秋刀鱼的年际丰度变化，我们使用广义线性模型（GLM）在1982-2018年间研究了扩展的日本标准化单位捕捞量（esCPUE）。解释性变量包括总和非传统捕捞努力（Ettl和Ent）和环境因素的代理。由于esCPUE代表两年类别，因此每个环境变量在t -1年和t年平均，对应于t年中的esCPUE。ETTL和耳鼻喉科进行平均年笔- 2和T-1 ，假设一年捕鱼牛逼影响一年生物质T + 1。我们比较了具有不同解释变量的四个GLM：（a）仅环境因素，（b）仅捕捞努力（无相互作用），（c）环境因素和捕捞努力（无相互作用）以及（d）环境因素和捕捞努力（有互动，即时变效应）。关于AICc，最佳GLM的解释变量包括以下内容：Ent在1982–2015年和2016–2018年之间有不同的影响，冬季的黑潮回潮区（KRA）的海表水温度（SST），冬季的北太平洋涡旋振荡（NPGO），冬季的南振荡指数和海底生物量日本沙丁鱼。NPGO是浮游动物数量的替代物，KRA-SST可能会影响秋刀鱼的早期生长和成活率。我们假设太平洋秋刀鱼的丰度变化是由环境因素和渔业驱动的，自2016年以来，后者受到的不利影响更大。