Fishery managers have struggled for decades to rebuild stocks of Atlantic Cod Gadus morhua in the northwestern Atlantic Ocean, and the resolution of current fine-scale population structure will surely help those efforts. Using double digest restriction-site associated DNA sequencing, we analyzed 248 adult and 215 juvenile Atlantic Cod collected from areas bordering the Canada–USA boundary in 2017–2018. Chromosomal inversions from linkage group (LG) 2 and LG 7 contribute the largest amount of variance to the data set. A southwesterly decrease in the proportion of LG 1 inversion haplotypes may indicate gene flow from areas north of 45°N. Samples from both the northern Gulf of Maine and Bay of Fundy were genetically distinct from all other samples, suggesting that local spawning groups may still be active. Genetic similarities between Atlantic Cod from Browns Bank and eastern Georges Bank indicate that transborder gene flow is ongoing. These results will help to better define the stocks in order to guide the implementation of management strategies in the USA and Canada, which should consider rebuilding exhausted and genetically isolated populations.

中文翻译：

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加拿大和美国之间的跨界基因流动和更广阔的缅因湾地区大西洋鳕鱼的精细种群结构

渔业管理人员已经奋斗了几十年重建大西洋鳕鱼的股票鳕鳕在大西洋西北部，目前精细规模的人口结构的解决必将有助于这些努力。使用双酶切限制位点相关的 DNA 测序，我们分析了 248 条成年大西洋鳕鱼和 215 条幼年大西洋鳕鱼，这些鳕鱼在 2017 年至 2018 年间从加拿大-美国边界接壤的地区收集。连锁群 (LG) 2 和 LG 7 的染色体倒位对数据集的方差贡献最大。LG 1 反转单倍型比例向西南下降可能表明基因来自北纬 45°以北地区。缅因湾北部和芬迪湾的样本在遗传上与所有其他样本不同，这表明当地产卵群可能仍然活跃。布朗斯银行和东乔治银行的大西洋鳕鱼之间的遗传相似性表明跨境基因流动正在进行中。