Since most marine benthic species experience a pelagic larval phase, scales of dispersal are key determinants of population dynamics. Biologically derived marine foam has been suggested to increase chances of fertilisation and reduce dispersal of larvae of short-live duration (hours), thus maintaining localised intertidal populations. The present study examined the role sea-foam plays as a mechanism of physical retention/accumulation for long lived (weeks) invertebrate larvae that are relatively long-lived (weeks). Larvae were collected using a submersible pump at two sites along the south-east coast of South Africa, where intertidal assemblages are dominated by beds of mussels and barnacles. Sampling took place on six occasions in 2015–2016, during events of high sea-foam production and periods of no foam accumulation. Foam/water was collected from the surface and bottom of tidal channels. There was no difference in abundance of larvae of any of the invertebrate taxa examined, whether foam was present or absent. Regardless of foam state, barnacle and polychaete larvae were mostly associated with the surface of the short water column at the tidal channels. This study highlights how the very nearshore environment may play a key role in limiting scales of larval dispersal, but especially how the effects of physical processes can be taxon-specific, depending on the larval duration and characteristics.

由于大多数海洋底栖生物都经历了上层幼体期，因此扩散规模是种群动态的关键决定因素。已提出生物来源的海洋泡沫会增加受精的机会，并减少短寿命（小时）的幼虫的扩散，从而保持局部潮间带种群。本研究研究了泡沫对于长寿（几周）相对长寿（几周）的无脊椎动物幼体的物理保留/积累机制的作用。幼虫是使用潜水泵在南非东南沿海的两个地点采集的，潮间带组合以贻贝和藤壶为主。在2015-2016年期间，在高泡沫生产和无泡沫积累期间，共进行了六次采样。从潮汐通道的表面和底部收集泡沫/水。无论是否存在泡沫，所检查的任何无脊椎动物分类单元中幼虫的丰度都没有差异。无论泡沫状态如何，藤壶和多毛幼虫大多与潮水道上短水柱的表面有关。这项研究强调了近岸环境如何在限制幼虫扩散规模中发挥关键作用，但尤其是取决于幼虫的持续时间和特征，物理过程的影响如何是特定分类群的。藤壶和多毛幼虫大多与潮水道上短水柱的表面有关。这项研究强调了近岸环境如何在限制幼虫扩散规模中发挥关键作用，但尤其是取决于幼虫的持续时间和特征，物理过程的影响如何是特定分类群的。藤壶和多毛幼虫大多与潮水道上短水柱的表面有关。这项研究强调了近岸环境如何在限制幼虫扩散规模中发挥关键作用，但尤其是取决于幼虫的持续时间和特征，物理过程的影响如何是特定分类群的。