Shellfish have been introduced to countries beyond their native distributions in order to develop new fisheries, but the success of such translocations has been variable. In 2003 and 2006, adult trochus (Rochia nilotica), a herbivorous coral reef gastropod, were translocated from Fiji and Vanuatu to Samoa. This translocation extended their natural range and created a new fishery in Samoa. In 2018, we had the opportunity to assess the population structure of trochus stocks at 28 sites around Samoa's two main islands using underwater visual censuses along transects. This assessment revealed that the distribution of populations showed no correspondence with initial translocation sites. Densities of trochus were spatially variable, and very high (>500 individuals/ha) at some sites. Size‐frequency distributions also varied among sites, yet all populations contained some large individuals. There was no evidence of competitive dominance of trochus over native gastropods or negative impacts to coral communities. This study shows that stocked shellfish such as trochus can develop to exploitable population levels within 15 years. Translocations of marine organisms must be considered with great caution. Our study indicates that livelihood benefits of introducing alien shellfish species are likely to be spatially variable. Translocations of the right species could support food webs and provide further food security and livelihood options to coastal fishing communities.

中文翻译：

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萨摩亚在珊瑚礁上引进的鳟鱼（天足目）的种群定殖

为了发展新的渔业，贝类已被引入本国分布以外的国家，但是这种易位的成功程度却是可变的。在2003年和2006年，成年成年鳟（Rochia nilotica），一种草食性珊瑚礁腹足动物，从斐济和瓦努阿图转移到萨摩亚。这种易位扩大了他们的自然范围，并在萨摩亚创造了新的渔业。2018年，我们有机会使用沿剖面的水下视觉普查评估了萨摩亚两个主要岛屿周围28个地点的鳟鱼种群结构。该评估表明，人口分布与最初的易位地点没有对应关系。tro的密度在空间上是可变的，并且在某些地方非常高（> 500个人/公顷）。站点之间的大小频率分布也有所不同，但是所有人口都包含一些大个体。没有证据表明鳟鱼比本地腹足动物更具竞争优势，也没有对珊瑚群落造成负面影响。这项研究表明，放养的贝类（例如鳟鱼）可以在15年内发展到可利用的种群水平。必须非常谨慎地考虑海洋生物的易位。我们的研究表明，引进外来贝类物种的生计利益在空间上可能是可变的。正确物种的转移可以支持食物网，并为沿海捕鱼社区提供进一步的粮食安全和生计选择。