The Rocky Mountain ridged mussel (Gonidea angulata) is a bivalve species whose Canadian range is limited to the Okanagan Valley, British Columbia. In 2019, conflicts between habitat protection for the mussel and potential habitat alteration to control the invasive Eurasian watermilfoil (Myriophyllum spicatum) (milfoil), led to a decision to maintain the status of the mussels as Special Concern under Canada’s Species at Risk Act (SARA) rather than classify it as Endangered. Milfoil control can cause direct mortality and/or burial of the mussels, but there had been no systematic study of the impacts of milfoil control on mussel beds. The purpose of this study was to address knowledge gaps by delineating known mussel beds and potential overlap with milfoil to provide information for management decisions that balance the needs of native species protection and invasive species control. Rocky Mountain ridged mussels in three reference locations were enumerated using snorkel surveys. The presence and distribution of milfoil was documented in relation to five sites within these three locations. Milfoil was encroaching on one site, causing some changes to the substrate. At other sites, the differences in the depth and distribution of the mussel and the milfoil could allow milfoil control without damaging the mussel beds. It is recommended that, before milfoil removal near known mussel beds be undertaken, a detailed site evaluation be conducted to determine potential impacts. This study suggests presumed impediments to co-managing the mussels and controlling an invasive species should not preclude classifying the mussels as Endangered and affording protections under SARA.

中文翻译：

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绘制落基山山脊贻贝床，初步确定加拿大范围内重叠的欧亚水乳清

落基山脊贻贝（Gonidea angulata）是双壳类，其加拿大范围仅限于不列颠哥伦比亚省的Okanagan谷地。2019年，贻贝栖息地保护与控制入侵性欧亚水母（Myriophyllum spicatum）（milfoil）的潜在栖息地改变之间的冲突，导致决定根据加拿大《濒危物种法》（SARA）维持贻贝作为特别关注的地位），而不是将其归类为“濒危”。叶控制可导致贻贝直接死亡和/或埋葬，但尚未有系统研究study叶控制对贻贝床的影响。这项研究的目的是通过划定已知的贻贝床和可能与白花苜蓿重叠的方法来解决知识空白，从而为平衡本地物种保护和入侵物种控制需求的管理决策提供信息。使用浮潜调查对落基山在三个参考地点的贻贝进行了枚举。记录了在这三个地点中五个地点相关的黄芪的存在和分布。Milfoil侵占了一个部位，导致底材发生了一些变化。在其他地方，贻贝和徐娘子在深度和分布上的差异可以控制徐徐而不破坏贻贝床。建议在对已知贻贝床附近的三叶草进行去除之前，应进行详细的现场评估以确定潜在的影响。