Spatial and temporal patterns of meiofaunal diversity in coastal ecosystems of Espírito Santo, Brazil

Abstract

The term meiofauna applies to benthic metazoans with sizes ranging between 50µm and 500µm.These animals are ubiquitous in freshwater and marine ecosystems at low or high depths.Meiofauna plays a key ecological role in marine sediments, acting in several ecological and biogeochemical processes, linking marine trophic levels, and are broadly used as bioindicators to assess environmental impacts. Due to its small size and high diversity, meiofauna identification requires extensive work and time of specialists on different phyla. The use of DNA-based approaches has been proposed as an alternative to the study of the meiofauna from environmental samples (Metabarcoding). This thesis seeks to investigate, using metabarcoding, spatial and temporal patterns of meiofauna diversity in different coastal ecosystems in southeastern Brazil. Chapter 1 presents a general introduction to the central theme of this Thesis, highlighting the importance of this type of study and presenting the objectives of subsequent chapters. In Chapter 2, a transition process was observed in the composition and diversity of meiofauna in the Rio Doce estuary at different times after a mining tailings disaster. In Chapter 3 the data obtained suggested greater phylogenetic diversity and differences in the benthic assemblage composition associated with high-density rhodolith beds. Chapter 4 demonstrates the influence of seasonality and spatial and ecological factors on the diversity, abundance, and composition of meiofauna, in additionto indicating the existence of an ecological filter between sandy beaches and tide pools. Chapter 5 presents the general conclusions obtained from this Thesis, and presenting possible future research that may benefit fromthe results presented here.