1999 - 2010 Alien species of Bugula (Bryozoa) along the Atlantic coasts of Europe Surveys of Marinas and Harbours

Three apparently non-native species of Bugula occur in marinas and harbours in Atlantic Europe. The most common, B. neritina, was known from a few sites in southern Britain and northern France during the 20th century, following its discovery at Plymouth by 1911. During the 1950-60s it was abundant in a dock heated by power station effluent at Swansea, south Wales, where it flourished until the late 1960s, while water temperatures were 7-10°C above ambient. It disappeared after power generation ceased, when summer temperatures probably became insufficient to support breeding. Details of disappearances have not been recorded but B. neritina was not seen in Britain between c1970 and 1999. Since 2000, it has been recorded along the south coast of England, and subsequently in marinas in the southern North Sea, Ireland and southern Scotland, well to the north of its former range, as well as along the Atlantic coast from Spain to The Netherlands. It has also been introduced to outlying localities such as the Azores and Tristan da Cunha. We report that this rapidly spreading form has the same COI haplotype as B. neritina currently invasive elsewhere in the world. B. simplex has been reported less, with 1950s records from settlement panels in some Welsh docks. It has not been targeted in most recent marina surveys but has been observed in southwest England, Belgium and The Netherlands. There are almost no recent records of B. stolonifera, though it was probably introduced to a few British and Irish ports prior to the 1950s. Its current status in most of western Europe is unknown but it has been reported as expanding throughout most of the world during the last 60 years. Having poorly known distributions, B. simplex and B. stolonifera should be recorded during future monitoring of alien species in Atlantic Europe. Illustrations to aid identification are included for all three species.

大西洋欧洲的码头与港口中存在三种明显的非本地Bugula属物种。其中最常见的B. neritina，自1911年在普利茅斯被发现后，20世纪期间已在英国南部及法国北部的若干地点有记录。20世纪50至60年代，该物种在威尔士南部斯旺西一处由电站废水加热的码头中大量存在，在水温较环境温度高7-10°C的条件下，其繁盛状态持续至60年代末。电站停止发电后，夏季水温可能不足以维持其繁殖，该物种遂消失。其消失的具体细节未被记录，但在约1970至1999年间，英国境内未再发现B. neritina。2000年以来，该物种在英格兰南海岸被记录，随后在北海南部、爱尔兰及苏格兰南部的码头中出现——这些区域远超出其原有分布范围的北部——同时也见于从西班牙到荷兰的大西洋沿岸。此外，它还被引入至亚速尔群岛及特里斯坦-达库尼亚群岛等偏远地区。我们的研究表明，这一快速扩散的种群具有与当前在全球其他地区入侵的B. neritina相同的细胞色素c氧化酶亚基I单倍型（COI haplotype）。

B. simplex的记录较少，20世纪50年代在威尔士部分码头的附着板上有其记录。近期多数码头调查未将其列为目标物种，但在英格兰西南部、比利时及荷兰均有观测记录。B. stolonifera几乎无近期记录，尽管其可能在20世纪50年代前已被引入英国及爱尔兰的若干港口。该物种在西欧大部分地区的现状未知，但据报道，过去60年间其在全球多数地区的分布范围正在扩大。由于B. simplex和B. stolonifera的分布情况尚不明确，未来在大西洋欧洲开展外来物种监测时应记录这两种物种。文中包含有助于这三种物种鉴定的插图。