Dissolved calcium concentration [Ca²⁺] is thought to be a major factor limiting the establishment and thus the spread of invasive bivalves such as zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels. We measured [Ca²⁺] in 168 water samples collected along ~100 river-km of the lower Columbia River, USA, between June 2018 and March 2020. We found [Ca²⁺] to range from 13 to 18 mg L⁻¹ during summer/fall and 5 to 22 mg L⁻¹ during the winter/spring. Previous research indicates that [Ca²⁺] < 12 mg L⁻¹ are likely to limit the establishment and spread of invasive bivalves. Thus, our results indicate that there is sufficient Ca²⁺ in most locations in the lower Columbia River to support the establishment of invasive dreissenid mussels, which could join the already widespread and abundant Asian clam (Corbicula fluminea) as the newest invader to an already heavily invaded Columbia River ecosystem. These new data provide important measurements from a heretofore undersampled region of the Columbia River and have important implications for the spread of invasive bivalves and, by extension, the conservation and management of native species and ecosystems.

中文翻译：

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美国哥伦比亚河下游的钙浓度通常足以支持侵入性双壳贝类传播

溶解钙浓度 [Ca ²⁺ ] 被认为是限制侵入性双壳类动物如斑马 ( Dreissena polymorpha ) 和斑驴 ( Dreissena bugensis ) 贻贝的建立和传播的主要因素。我们测量了2018 年 6 月至 2020 年 3 月期间沿美国哥伦比亚河下游约 100 条河流公里收集的 168 个水样中的[Ca ²⁺ ]。我们发现 [Ca ²⁺ ] 的范围为 13 至 18 mg L ^-1夏季/秋季和冬季/春季5 至 22 mg L ^-1。先前的研究表明 [Ca ²⁺ ] < 12 mg L ^-1可能会限制侵入性双壳类动物的建立和传播。因此，我们的结果表明，在哥伦比亚河下游的大多数地方都有足够的 Ca ²⁺来支持入侵的德莱森贻贝的建立，这可能与已经广泛分布和丰富的亚洲蛤（Corbicula fluminea）一起成为已经存在的最新入侵者。严重入侵哥伦比亚河生态系统。这些新数据提供了迄今为止对哥伦比亚河采样不足的地区的重要测量结果，对入侵双壳类动物的传播以及本地物种和生态系统的保护和管理具有重要意义。