Lipid biomarkers in Lake Enol (Asturias, Northern Spain): Coupled natural and human induced environmental history

Plant sterols, such as β-sitosterol, campesterol and stigmasterol, were significantly present in the cores. In addition, fecal stanols, such as 24-ethylcoprostanol from herbivores, were present, thereby indicating a continuous and significant pollution input derived from these animals since the 17th century, being more important in the last 20 years.