Quantifying scale-dependent patterns and linking ecological to environmental variation is required to understand mechanisms regulating biodiversity. We conducted a large-scale survey in rocky shores along the SE Brazilian coast to examine spatial variability in body size and density of an intertidal barnacle (Chthamalus bisinuatus) and its relationships with benthic and oceanographic predictors. Both the size and density of barnacles showed most variation at the smallest spatial scales. On average, barnacle body size was larger on shores located in areas characterised by higher chlorophyll levels, colder waters, low wave action and low influence of freshwater. Barnacles were more abundant at wave-exposed shores. We identified critical scales of spatial variation of an important species and linked population patterns to essential environmental predictors. Our results show that populations of this barnacle are coupled to scale-dependent oceanographic variation. This study offers insights into the mechanisms regulating coastal populations along a little studied coastline.

需要量化依赖于尺度的模式并将生态与环境变化联系起来，以了解调节生物多样性的机制。我们在巴西东南部海岸的岩石海岸进行了大规模调查，以检查潮间带藤壶（Chthamalus bisinuatus) 及其与底栖和海洋预测因子的关系。藤壶的大小和密度都在最小的空间尺度上表现出最大的变化。平均而言，位于具有较高叶绿素水平、较冷水域、低波浪作用和低淡水影响区域的海岸上的藤壶体型较大。在海浪暴露的海岸，藤壶更为丰富。我们确定了重要物种空间变异的关键尺度，并将种群模式与基本环境预测因子联系起来。我们的结果表明，这种藤壶的种群与依赖于尺度的海洋变化有关。这项研究提供了对沿很少研究的海岸线调节沿海人口的机制的见解。