Diversity assessment of benthic macroinvertebrates, yeasts, and microbiological indicators along a longitudinal gradient in Serra do Cipó, Brazil

Abstract

The main goals of this study were: 1) to evaluate the structure, diversity, and functional trophic group composition of benthic macroinvertebrate communities; 2) to characterize water quality in the headwaters of the Doce river watershed, based on physical, chemical, and biological parameters (benthic macroinvertebrates, fecal coliforms, heterotrophic bacteria, and yeasts); and 3) to contribute to the knowledge of the structure and function of longitudinal gradients in lotic ecosystems in Brazil. A total of 60 benthic macroinvertebrate taxa were identified, the dominant group being the aquatic insects, with 50 families distributed in 8 orders. The dry period presented higher values of taxonomic richness and total density of benthic macroinvertebrates. A decreasing gradient was observed in these variable values from the 3rd order stretch down to the 6th order stretch. The highest Shannon-Wiener diversity values were found in the rainy period in the 3rd order stretches, which presented well-developed riparian forest. Besides the 3rd order stretches, the Pielou evenness index values were also high in the 6th order stretch. The collectors, together with the scrapers, predominated in the benthic macroinvertebrate communities in all river stretches, except in the 2nd, 4th, and 5th order stretches in the rainy period, where communities were dominated by filterers. The shredders and predators presented low densities for all river stretches. All microbiological variables presented low levels. Due to the high counts of heterotrophic bacteria and coliforms, the studied river stretches presented inadequate potability but adequate balneability levels. The results suggest that the structure, diversity, and composition of the benthic macroinvertebrate communities are influenced by the trophic resource availability, seasonality, and sediment heterogeneity. The microbiological results of this study allow inferring that the waters from Serra do Cipó have excellent potential for recreational use and as future sources of water for human consumption.

Leaf degradation of Salix humboldtiana Willd. (Salicaceae) and invertebrate colonization in a subtropical lake (Brazil)

“…These organisms are adapted to feed on FPOM (Wallace and Webster, 1996). In lotic environments, they are usually the most abundant group (Lugthart and Wallace, 1992;Callisto et al, 2001Callisto et al, , 2004Carvalho and Uieda, 2009b). According to Richardson (1992) and Grubbs et al (1995), the dominance of this group is associated with the accumulation of FPOM from its own detritus or from organic particles arising from the seston on the detrital surface.…”

Spatial and temporal distribution of the zoobenthos community during the filling up period of Porto Primavera Reservoir (Paraná River, Brazil)

“…Noticeable influence of seasonality is also expected, specially in the upper and middle zones of the reservoir, which are more susceptible to dry/wet conditions. Callisto et al (2001Callisto et al ( , 2004 studying the macrobenthic community from Serra do Cipó (MG) found that structural and compositional modification of this community occurs due to changes in trophic resource availability. According to the authors, the physical disturbance of the substrate (observed in the rainy period) causes the resuspension of sediment on the bottom and, as a consequence, the modification of the functional trophic groups.…”

Macroinvertebrate fauna associated with Pistia stratiotes and Nymphoides indica in subtropical lakes (south Brazil)

“…In some groups, however, it was not possible to go further than Phylum. This classification level is widely used in studies to characterize macroinvertebrate communities, especially in South American countries where the species of organisms are unknown and there are limited human and financial resources (Alba-Tercedor and Sánchez-Ortega, 1988;Feldman and Connor, 1992;Callisto et al, 2000;Marques and Barbosa, 2001;Stenert et al, 2002 andCallisto et al, 2004;among others).…”