Robert Chloé, Alves Monteiro Homère J, Le Moan Alan, Tanguy Arnaud, Laugen Ane T, Hemmer-Hansen Jakob, Strand Åsa, De Wit Pierre
Department of Marine Sciences, Tjärnö Marine Laboratory University of Gothenburg Strömstad Sweden.
Center for Evolutionary Hologenomics, University of Copenhagen Copenhagen K Denmark.
Evol Appl. 2025 Mar 31;18(4):e70096. doi: 10.1111/eva.70096. eCollection 2025 Apr.
Stocks of the European flat oyster, , have collapsed due to overfishing, habitat destruction, and pathogen outbreaks across most of their distribution range. Nonetheless, as a result of lower exploitation pressure and the absence of pathogens in the most northern part of the range, a large part of the remaining wild population can be found in relatively high densities in Scandinavia, a region in Northern Europe. However, despite recent studies focusing on flat oyster population structure along the European coast, little is known about the population structure of oysters in the Skagerrak marginal sea in Scandinavia, and how it is related to neighbouring regions. This study, therefore, aimed to investigate the population structure of flat oysters in Scandinavia, with a special emphasis on the Skagerrak. We gathered low-coverage whole-genome sequencing data from oysters in Sweden, Norway, and Denmark, the three countries that border the Skagerrak. Genetic diversity appeared to be homogeneously distributed over the sampled area in the Skagerrak, while samples collected from the east coast of Denmark and from a location with known historical farming activity on the Norwegian West Coast were genetically distinct from Skagerrak samples. A genetic barrier analysis indicated barriers to gene flow in the Baltic Sea transition zone and on the west coast of Norway. Overall, our results suggest that flat oysters from the Swedish Skagerrak coasts form a single panmictic population that is distinct from neighbouring seas, potentially allowing for regional management of stocks and restoration translocations in the area. However, the genetic composition of donor and recipient stocks should be assessed on a case-by-case basis, genetic diversity effects of hatchery practices should be monitored, and biosecurity measures need to be considered prior to any movement of stock.
欧洲扁蛎（ ）的种群数量因过度捕捞、栖息地破坏以及病原体在其大部分分布范围内的爆发而崩溃。尽管如此，由于在该分布范围最北部的开发压力较低且没有病原体，在北欧地区斯堪的纳维亚半岛仍能发现剩余野生种群的很大一部分以相对较高的密度存在。然而，尽管最近的研究聚焦于欧洲海岸沿线扁蛎的种群结构，但对于斯堪的纳维亚半岛斯卡格拉克边缘海的牡蛎种群结构及其与邻近地区的关系却知之甚少。因此，本研究旨在调查斯堪的纳维亚半岛扁蛎的种群结构，特别关注斯卡格拉克地区。我们从与斯卡格拉克接壤的瑞典、挪威和丹麦的牡蛎中收集了低覆盖度的全基因组测序数据。斯卡格拉克采样区域内的遗传多样性似乎分布均匀，而从丹麦东海岸以及挪威西海岸一个有已知历史养殖活动地点采集的样本在基因上与斯卡格拉克样本不同。遗传屏障分析表明在波罗的海过渡区和挪威西海岸存在基因流动障碍。总体而言，我们的结果表明，来自瑞典斯卡格拉克海岸的扁蛎形成了一个单一的随机交配种群，与邻近海域不同，这可能允许对该地区的种群进行区域管理和恢复性迁移。然而，捐赠种群和接收种群的遗传组成应逐案评估，应监测孵化场操作对遗传多样性的影响，并且在任何种群迁移之前都需要考虑生物安全措施。
