Evaluation of phenolic content of wrack debris on estuarine beaches: The effect on upper beach macrofauna

Wrack supply represents the main organic input in sandy beaches ecosystems and is a common feature of around world. The chemical composition wrack important determining extent rate decay; particular, phenolic compounds may affect consumption rates by wrack-associated macrofauna and, consequently, modify nutrient processing recycling beaches. aim this research was to investigate possible links between content supplies macrofaunal community inhabiting them. To achieve this, patches three NW coast Spain were analysed contents distribution, both at spatial temporal scales, assessed. samples collected along two shore-parallel transects, coinciding with lines previous tidal deposition. results showed general distribution beach-cast according their position on beach. Thus, distinct zones identified: “spring-tide deposited” zone located upper beach close base dunes composed material lowest concentrations; “freshly deposits containing highest concentrations deterrent compounds. Nevertheless, only supratidal grazers, mostly linked fresh deposits, have shown slightly negative association abundance increasing stranded macroalgae. lack consistent pattern occupation decayed drift detected suggests species could be selecting habitats for reasons other than content.