ABREU, R., FIGUEIRA, C., ROMÃO, D., BRANDÃO, J., FREITAS, M.C, ANDRADE, C., CALADO, G., FERREIRA, C., CAMPOS, A., PRADA, S. (2016) - Sediment characteristics and microbiological contamination of beach sand – A case–study in the archipelago of Madeira. Science of the Total Environment 573:627–638.

​Beach sand can harbour pathogenic and opportunistic microorganisms, as well as faecal indicator bacteria that influence directly the bathing water quality. Pathogenic and opportunistic microorganisms often raise concern ofexposure during beach related recreational activities. In this work, three different types ofsandy beaches (nat- ural basaltic, natural calcareous and artificial calcareous) of the Archipelago of Madeira (Portugal) were sampled for bacterial and fungal contaminants and grain size distribution, during four years (2010−2013). Following an extreme weather event in 2010, the faecal indicator bacteria levels spiked, returning to base levels shortly there- after. The same phenomenon occurredwith fungi, where potentially pathogenic fungi were the dominant group. Yeast-like fungi and dermatophytes were, however, mainly associated to months of higher usage by recreational users. Statistical analysis showed higher contamination of sediment in artificial beaches compared to natural beaches and granulometry and chemical composition of sand did not influence in the microbial loads. Instead, bather density and the influence ofcoastal protection structures needed tomaintain the volumeofartificial beach sand regarding the removal potential ofwave induced currents are obvious influencing factors.