Abstract Growth in size stops at the terminal molt (molt-to-maturity) for the eastern Bering Sea snow and Tanner crab (Chionoecetes opilio and C. bairdi) and understanding size-at-maturity (SAM) dynamics is critical to manage their fisheries, which target and retain large mature males. Bottom trawl survey data from 1982 to 2017 were analyzed with correlations and spatial regressions to identify temporal and spatial patterns of SAM and size-specific proportions mature (PM) for newshell (recently molted) crab of each sex of each species. While substantial annual variability in SAM was estimated, no long-term directional trends were estimated for either species. Recruitment variability was likely the major driver of temporal trends in SAM for both species, rather than variable ocean temperatures or other possible factors. Recruitment abundances and SAM were negatively correlated for female snow crab but positively correlated for male snow crab and both sexes of Tanner crab. Male and female snow crab SAM had similar periodicities as snow crab recruitment. SAM spatial patterns were relatively stable at decadal time-scales for both species. Annual temporal variability in PM was moderate to negligible for both species and decadal-sale variability was modest, indicating temporally stable size-specific maturation probabilities. Comparison of SAM and PM regression results show strong effects of ontogenetic movement on spatial patterns of SAM for male snow crab. Intra- and inter-species comparisons allowed for broader understanding of SAM dynamics. Strong periodicity of male snow crab SAM may have utility for fisheries management. Elucidating the mechanisms responsible for periodic recruitment for these species will help provide a more complete understanding of both SAM dynamics and general population dynamics. With increasing ocean temperatures in the EBS, the mean size of mature crab for these species may increase but would certainly be accompanied by a decrease in snow crab abundance, the more stenothermic of the two species.

中文翻译：

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白令海东部雪蟹和坦纳蟹（Chionoecetes opilio 和 C. bairdi）成熟期大小的时空变异性

摘要 白令海东部雪和坦纳蟹（Chionoecetes opilio 和 C. bairdi）在蜕皮末期（蜕皮到成熟期）的体型增长停止，了解成熟期体型 (SAM) 动态对于管理其渔业至关重要，其目标是并保留大型成熟雄性。对 1982 年至 2017 年的底拖网调查数据进行了相关性和空间回归分析，以确定 SAM 的时间和空间模式以及每个物种的每个性别的新壳（最近蜕皮）螃蟹的成熟比例（PM）。虽然估计 SAM 的年度变化很大，但没有估计任一物种的长期定向趋势。募集变异性可能是两个物种 SAM 时间趋势的主要驱动因素，而不是海洋温度变化或其他可能的因素。雌性雪蟹的募集丰度和 SAM 呈负相关，而雄性雪蟹和丹纳蟹的雌雄两性的募集丰度和 SAM 呈正相关。雄性和雌性雪蟹SAM与雪蟹招募具有相似的周期性。两个物种的 SAM 空间模式在十年时间尺度上相对稳定。PM 的年度时间变化对于这两个物种来说都是中等到可以忽略不计，十年销售变化是适度的，表明时间上稳定的大小特定的成熟概率。SAM 和 PM 回归结果的比较表明个体发育运动对雄性雪蟹 SAM 的空间格局有很强的影响。种内和种间比较允许更广泛地了解 SAM 动态。雄性雪蟹SAM的强周期性可能对渔业管理有用。阐明负责这些物种定期招募的机制将有助于更全面地了解 SAM 动态和一般种群动态。随着 EBS 中海洋温度的升高，这些物种的成熟蟹的平均大小可能会增加，但肯定会伴随着雪蟹丰度的减少，这两个物种的温度更高。