Glacial recession in Andean North-Patagonia (Argentina): Microbial communities in benthic biofilms of glacier-fed streams

VEGA R.; BASTIDAS NAVARRO, M.; MARTYNIUK, N.; BALSEIRO, E.; MODENUTTI, B.

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2023

0018-8158

Global climate change produces important shifts in the glacial runoff, modifying therelative contributions of meltwater and glacial clay discharges into headwater streams.Physical and chemical factors of glacier-fed streams are affected, such as totalsuspended solids (TSS), and nutrient concentrations. Here, we analyze thecomposition of the biofilm bacterial community by 16S rRNA sequencing along aglacier-fed network (Upper Río Manso) located in North Patagonian Andes (Argentina).We also analyzed changes in environmental factors in relation to the bacteriacomposition in different seasons (spring, summer, and autumn). Our results showedthat the dominant phyla were Proteobacteria, Cyanobacteria, Bacteroidota,Actinobacteriota, and Acidobacteriota. Bacterial community composition changeslongitudinally and seasonally in relation to glacial influence (TSS and phosphorusconcentrations). We identified phylotypes of Proteobacteria (Polaromonas,Rhodoferax, and Methylotenera) that were only present in headwaters of the fluvial systems. In addition, Cyanobacteria also presented substantial changes along themain course of Manso River and among seasons. The increase of Cyanobacteriaabundance was favored by the glacial influence both longitudinally and seasonally.Overall our results contribute to the understanding of the patterns of biodiversity andbacterial composition under a constant glacial retreat.