As habitat-forming species continue to decline globally, it is important to understand how associated communities respond to habitat loss and fragmentation. Changes in the density and spatial configuration of habitat have important consequences for associated communities. However, tests of these factors are often confounded by morphological variation of habitat-formers, which can be resolved by using standardised habitat-mimics. Furthermore, few studies have incorporated the role of predators in mediating the observed effects. To test whether predators mediate the abundance of invertebrates among algal habitats of varying configuration (isolated vs patches, and positions within patches), we placed macroalgal mimics into subtidal estuarine habitats for one month to sample epifaunal communities. At the same time, we conducted underwater video surveys of fish communities to quantify fish communities and their feeding behaviour among the artificial habitats. Isolated habitats did not differ from patch habitats, however, patch edges had the highest epifaunal abundance, where fish were least commonly observed. Observed fish feeding was highest in the middle of patches and increased fish observations and feeding in habitats with reduced epifaunal communities suggest that mesopredatory fish are mediating epifauna in patches, with predation pressure altered by the spatial configuration of the habitat. This contrasts to previous studies that focus on predators that congregate outside patches and suggest that fragmentation leads to reduced invertebrate abundance at habitat edges in contrast to centres. However, this study highlights that in habitat patches housing small mesopredators that also benefit from the increased structure, the centre of the patch experiences higher predation and therefore fewer epifauna in contrast to patch edges and individual algal mimics.

随着形成栖息地的物种在全球范围内持续减少，了解相关社区如何应对栖息地丧失和破碎化至关重要。生境的密度和空间配置的变化对相关社区产生重要影响。但是，这些因素的测试通常与栖息地形成者的形态变化混淆，可以通过使用标准化的栖息地模拟物来解决。此外，很少有研究纳入掠食者在介导观察到的影响中的作用。为了测试捕食者是否介导不同构造的藻类栖息地（隔离的vs斑块和斑块内的位置）之间的无脊椎动物数量，我们将大型藻类模拟物放置到潮下河口栖息地中一个月，以对表生动物群落进行采样。同时，我们对鱼类群落进行了水下视频调查，以量化鱼类群落及其在人工生境中的摄食行为。孤立的栖息地与斑块栖息地没有什么不同，但是斑块边缘的表生真菌丰度最高，鱼类很少见。在斑块中部观察到的鱼类摄食最高，对鱼类的观察增多，并且在表生动物群落减少的生境中进食，这表明中捕捞鱼类正在斑块中介导表生动物，其捕食压力随生境的空间配置而改变。这与以前的研究相反，后者的研究集中于捕食者，它们聚集在斑块的外部，与中心相比，破碎导致栖息地边缘无脊椎动物的数量减少。然而，