Reliable information on the structure of fished populations can help align management units with the ecology of target species. One way to attain such information lies in accurately defining the scales at which groups of fish vary in key attributes – the chemical markers within otoliths providing well known examples. Here, motivated by current uncertainties around stock status and population structure within the Icelandic summer spawning (ISS) herring (Clupea harengus) stock, we use simulations to derive quantitative rules for assessing the spatial and temporal scales of otolith chemical variation in a Bayesian modelling setting. We then apply these rules to empirical otolith chemistry data from ISS herring sampled across their full distributional range, over three years, to tackle some open questions on nursery connectivity, fidelity and contributions to the fishery. Bayesian multivariate linear models (BMLMs) exposed differences in otolith elemental (Li, Mg, Mn, Zn, Sr, Ba) and stable isotopic (δ¹³C, δ¹⁸O) concentrations in nursery-resident age-1 and age-2 juveniles that generally scaled with distance among nurseries, and time between sampling events. Our simulation-based rules built confidence in the application of BMLMs to characterise ‘source’ populations within the juvenile dataset. These sources were subsequently treated as baseline samples in mixture models that revealed 1) strong evidence for nursery-site fidelity between age-1 and age-2, and 2) multiple nurseries as contributors to a fished age-3 population, irrespective of presumed nursery quality. While additional sampling is required to confirm these results and their relevance for management of herring stocks in Iceland and further afield, we note that the rules and models presented here can be easily adapted for a broader suite of fisheries applications where reliable methods for evaluating differences in multiple attributes among individuals, populations or stocks are needed.

关于捕捞种群结构的可靠信息有助于使管理单位与目标物种的生态保持一致。获得此类信息的一种方法在于准确定义鱼群在关键属性上不同的尺度——耳石内的化学标记提供了众所周知的例子。在此，受冰岛夏季产卵 (ISS) 鲱鱼 ( Clupea harengus) 股票，我们使用模拟得出定量规则，用于评估贝叶斯建模设置中耳石化学变化的空间和时间尺度。然后，我们将这些规则应用于来自国际空间站鲱鱼的经验耳石化学数据，该数据在三年多的整个分布范围内采样，以解决有关苗圃连通性、保真度和对渔业的贡献的一些开放性问题。贝叶斯多元线性模型 (BMLM) 暴露了耳石元素（Li、Mg、Mn、Zn、Sr、Ba）和稳定同位素（δ ¹³ C、δ ¹⁸）的差异O) 托儿所居民 1 岁和 2 岁幼鱼的浓度，通常随托儿所之间的距离和采样事件之间的时间成比例。我们基于模拟的规则建立了对 BMLM 应用的信心，以表征青少年数据集中的“源”种群。这些来源随后被视为混合模型中的基线样本，这些模型揭示了 1) 1 岁和 2 岁之间苗圃场保真度的有力证据，以及 2) 多个苗圃作为 3 岁捕捞种群的贡献者，而不管假定的苗圃质量。虽然需要额外抽样以确认这些结果及其与冰岛和更远地区鲱鱼种群管理的相关性，