Water quality indicator bacteria in natural wetlands from Paraguay-Brazil cross-border region on the Paraná river basin

Wetlands are one of the most threatened ecosystems globally; the increase in urbanization and agriculture means a change of soils that can affect the microbiological communities in these environments. This study assesses fecal bacteria bioindicators (FIB) in surface water from three first-studied natural wetlands in Itaipu Biosphere Reserve, one in an urban area (Piratiy wetland) and two in a dispersed rural area (Carapã and Limoy wetlands) in east and northeast of Paraguay. We detected bacterial counts of total coliforms (TC), fecal coliforms (FC) and Escherichia coli in all sampled sites with the lowest counts found in the urban wetland water (Piratiy TC: 35±7, FC: 15±7, E. coli: 25±7 CFU/mL) and highest count in wetlands waters in rural dispersed areas (Carapã TC: 105±7, FC: 10±0, E. coli: 105±7; and in Limoy TC: 210±14, FC: ˂1, E. coli: 30±14 CFU/mL). All FIBs were under the limits established in regional regulations for surface and freshwater waters. Although they showed no significative differences in bacterial counts according to their location (p=0.0609), this study contributes to the first data on these sites, demonstrating that the use of FIB would be suitable for monitoring natural wetlands waters and opens perspectives to further evaluate and establish reference limits to these essential ecosystems in the Upper Paraná Atlantic Forest Region.