Several previous studies of marine fish stocks have demonstrated time‐varying recruitment productivity and indicated that including time‐varying parameters can track process variation in recruitment. Few studies have synthesized signal‐to‐noise ratios and underlying reasons for time‐variation across stocks and regions. Using Peterman's productivity method (PPM), we provide a broad synthesis of time‐varying density‐independent productivity in 84 stocks across five regions of the United States. Of all stocks investigated, 50 were found to have time‐varying productivity, challenging assumptions on the stationarity of recruitment parameters and dependent reference points. Our results demonstrate the power of PPM for synthesizing the form and pattern of recruitment time‐variation among regions, including general summaries of directional change over time. Furthermore, our results show regional differences in time‐varying patterns, particularly the signal‐to‐noise ratio (SNR) of low‐ to high‐frequency variation. The SNR was lower in the California Current region than in two Atlantic regions and two Alaska regions. Generalized linear modelling used to synthesize results suggests that stocks with higher contrast in spawning stock biomass over time, standardized regardless of actual spawning stock size, were more likely to have time‐varying productivity than stocks with low contrast. The likelihood of time‐variation in productivity of a given stock was also found to be closely related to the autocorrelation of the recruitment time series. Such inter‐regional and inter‐stock comparisons of variation are vital in understanding the roles of local and global environmental change on fish productivity.

中文翻译：

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美国鱼类种群补充率的时间模式和区域比较


先前对海洋鱼类种群的几项研究已经证明了随时间变化的补充生产力，并表明包括随时间变化的参数可以跟踪补充过程的变化。很少有研究综合了信噪比以及股票和地区之间时间变化的根本原因。使用彼得曼的生产率方法 (PPM)，我们对美国五个地区的 84 只股票的随时间变化的密度无关的生产率进行了广泛的综合。在所有调查的股票中，有 50 只被发现具有随时间变化的生产力，这对招聘参数和相关参考点的稳定性假设提出了挑战。我们的结果证明了 PPM 综合区域间招募时间变化的形式和模式的能力，包括随着时间的推移方向变化的一般总结。此外，我们的结果显示了时变模式的区域差异，特别是低频到高频变化的信噪比（SNR）。加州海流区域的 SNR 低于两个大西洋区域和两个阿拉斯加区域。用于综合结果的广义线性模型表明，随着时间的推移，产卵种群生物量对比度较高的种群（无论实际产卵种群大小如何，均已标准化）比对比度较低的种群更有可能具有随时间变化的生产力。还发现给定股票的生产率随时间变化的可能性与招聘时间序列的自相关密切相关。这种区域间和种群间变化的比较对于理解当地和全球环境变化对鱼类生产力的作用至关重要。