Invasive non-indigenous crayfish species (NICS) are a global threat to local flora and fauna. Total eradication of an entire population of invasive NICS is a difficult task; several methods have been tested and are still being used, with varying success. Most methods reduce population size and control the species within the targeted area but do not majorly prevent further spread of NICS. However, construction of crayfish barriers can stop the spread of NICS and can therefore, be used to protect indigenous crayfish species (ICS). There are currently very few published scientific papers about this topic. This review reflects current knowledge on how to stop migration when NICS are established and provides useful information for the construction of barriers. The most important findings related to building a crayfish barrier are: the need for a vertical wall with an overhanging lip above the water surface; smooth sections to prevent crayfish from walking or climbing over the obstacle, combined with flow velocities of 0.65 m/s act as a barrier within the waterbody. Additionally, modifications to existing structures, bridges, culverts and dams reduce costs and increase effectiveness in stopping upstream migration of NICS. Barriers can negatively impact certain aquatic species, mainly benthic and slow swimming fish by preventing their migration and genetic exchange. However, they can have positive impacts for ICS and other indigenous organisms against the negative effects of NICS. Local legislation should support barrier construction to prevent the spread of invasive crayfish and other aquatic invaders to protect ark sites for ICS.

中文翻译：

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使用物理屏障阻止非本土小龙虾物种传播的审查

入侵的非本土小龙虾物种 (NICS) 是对当地动植物群的全球威胁。彻底根除所有侵入性 NICS 是一项艰巨的任务；几种方法已经过测试并仍在使用，取得了不同程度的成功。大多数方法减少种群规模并控制目标区域内的物种，但不能主要防止 NICS 的进一步传播。然而，小龙虾屏障的建造可以阻止 NICS 的传播，因此可用于保护本地小龙虾物种 (ICS)。目前关于这一主题的已发表的科学论文很少。该评论反映了在建立 NICS 时如何停止迁移的当前知识，并为构建障碍提供了有用的信息。与构建小龙虾屏障相关的最重要发现是：需要在水面上方有一个悬垂的垂直墙；光滑的部分以防止小龙虾行走或爬过障碍物，结合 0.65 m/s 的流速作为水体内的屏障。此外，对现有结构、桥梁、涵洞和水坝的改造可降低成本并提高阻止 NICS 向上游迁移的有效性。障碍可以通过阻止迁移和基因交换对某些水生物种产生负面影响，主要是底栖鱼类和游动缓慢的鱼类。然而，它们可以对 ICS 和其他本土生物产生积极影响，以抵御 NICS 的负面影响。地方立法应支持屏障建设，以防止入侵小龙虾和其他水生入侵者的传播，以保护 ICS 的方舟地点。