Fish functional diversity is less impacted by mining than fish taxonomic richness in an Amazonian stream system

Mining is an important human activity, but it strongly alters terrestrial and aquatic landscapes. Understanding the response of community-level descriptors is essential to plan monitoring and management strategies. In this context, we investigated differences in the environmental conditions and ichthyofauna (taxonomic and functional) structure in five pristine and four disturbed streams in a Central Amazon protected area sampled in the dry season of 2012. Additionally, we analyzed if taxonomic and functional structure exhibited similar spatial variation patterns among streams. Pristine streams exhibited higher richness and proportion of catfishes (Siluriformes) than disturbed streams, but no differences in the functional structure. The taxonomic and functional structure of the fish assemblages in the Saracá-Taquera National Forest varied concomitantly among the streams. Our results indicate that taxonomic-based metrics were more sensitive to the mining impacts in the Saracá-Taquera National Forest, probably because of the high functional redundancy of the local assemblages. We highlight the sensitivity of richness and proportion of siluriformes for monitoring stream fish assemblages in the Central Amazon.