The Pacific oyster, Magallana gigas, is an extremely successful invader with established populations in marine and estuarine habitats almost all over the world. Ecological implications of the introduction of this species to indigenous communities are well documented. However, the processes by which this species successfully establishes in a recipient community is still insufficiently understood. The early detection of the oyster at the island of Helgoland (North Sea) provided the ideal opportunity to investigate whether physical mechanisms, such as wave-exposure, influence their successful colonisation. We hypothesized that oyster colonisation benefits from wave-protected conditions. For this purpose, we evaluated colonisation success of M. gigas among wave-protected sites and wave-exposed sites along the island's pier system. The densities of M. gigas were significantly higher at wave-protected sites than at wave-exposed sites, and the frequency distributions of oyster lengths indicated better growth and higher survival rates in the harbours. This higher colonisation success at wave-protected sites may be explained by the relative retention time of water masses in the harbours, probably resulting in both reduced larval drift and lower energy demands for secretion formation (i.e. firmer binding to the substrate). The fact that the density of M. gigas can vary greatly on small spatial scales depending on exposure corroborates a multiple exposure sampling approach to monitor oyster populations in order to avoid potential overestimations of population sizes in given areas.

太平洋牡蛎Magallana gigas是非常成功的入侵者，几乎遍布世界各地的海洋和河口栖息地已建立种群。充分记录了将该物种引入土著社区的生态影响。但是，对于该物种在受体群落中成功建立的过程仍知之甚少。在黑尔戈兰岛（北海）的牡蛎的早期发现提供了一个理想的机会，以调查诸如波浪暴露等物理机制是否影响其成功定居。我们假设牡蛎定居受益于波浪保护条件。为此，我们评估了M的定植成功。吉加斯沿岛码头系统的防波堤和受波幅照射的地点之间。M的密度。受波浪保护的地点的海藻比暴露于波浪的地点的海藻的数量显着更高，牡蛎长度的频率分布表明港口的生长更好，成活率更高。波浪保护地点较高的定植成功率可以用水团在港口中的相对停留时间来解释，这可能导致幼虫漂移减少和分泌物形成的能量需求降低（即与底物的牢固结合）。M. gigas的密度 在较小的空间尺度上，其变化可能很大，这取决于暴露程度，从而证实了采用多重暴露抽样方法来监测牡蛎种群，以避免对给定区域内种群规模的潜在高估。