Cyanobacterial blooms are increasing in frequency, duration, and severity globally in freshwater ecosystems. The Laurentian Great Lakes are prone to toxin-producing cyanobacterial blooms and have experienced annually recurring blooms. Because of its oligotrophic nature, Lake Superior has been relatively free of bloom occurrences. However, in recent years, Dolichospermum blooms have occurred with increasing frequency, especially in the western arm. During a Dolichospermum bloom in 2018, opportunistic samples were collected from the offshore bloom and investigated with shotgun metagenomics. We identified a near-complete Dolichospermum genome that is highly similar to genomes from cultures recovered in Lakes Erie and Ontario. The genomes from the Laurentian Great Lakes are typified by their putative ability to produce a suite of secondary metabolites like anabaenopeptin, but not toxins like microcystin. Additionally, we recovered a Dolichospermum lemmermannii 16S rRNA gene from the bloom and using datasets collected from the epilimnion and sediments in Lake Superior show this organism is ubiquitous and that several strains may exist. While there is much to learn about Lake Superior cyanobacterial bloom development and triggers, understanding this organism is endemic to the region, what its genome is capable of and that specific strains may have provenance within the lake provides a distinct ecological basis for understanding and working towards a predictive framework for future blooms.

蓝藻水华在全球淡水生态系统中的频率、持续时间和严重程度都在增加。Laurentian Great Lakes 容易出现产毒蓝藻水华，并且每年都会出现反复水华。由于其贫营养性，苏必利尔湖相对没有水华发生。然而，近年来，长春花的发生频率越来越高，尤其是在西臂。在2018 年Dolichospermum开花期间，从近海开花中收集了机会样本，并用鸟枪宏基因组学进行了研究。我们发现了一个近乎完整的Dolicospermum基因组与在伊利湖和安大略省恢复的培养物中的基因组高度相似。来自 Laurentian Great Lakes 的基因组的典型特征是它们能够产生一系列次级代谢物，如鱼腥藻肽，但不产生毒素，如微囊藻毒素。此外，我们还回收了一种Dolichospermum lemmermannii来自开花的 16S rRNA 基因和使用从苏必利尔湖的表层和沉积物中收集的数据集表明，这种生物无处不在，并且可能存在几种菌株。虽然有很多关于苏必利尔湖蓝藻水华发展和触发因素的知识，但了解这种生物是该地区特有的，它的基因组有什么能力以及特定菌株可能在湖中出处为理解和努力提供了独特的生态基础。未来开花的预测框架。