Cerro Tambor from Huinay Scientific Field Station - December 2017

Microbial Ecology and Resistome of the Comau Fjord, Patagonia (42ºS)

The Comau Fjord is an estuarine system located in Northern Patagonia (42ºS), Chile. In this research project, we use the Comau Fjord as a model of anthropogenic impact because, while the land surrounding the fjord is protected (National Parks; private conservation), the fjord itself is home to the salmon/trout aquaculture industry. Aquaculture in Chile is known for using escesive amounts of antibiotics, where these are administered through medicated feed, and thus, excess goes to the fjord waters where it impacts the ecosystem.

In this research project, we want to understand the composition, structure, and taxonomic and functional diversity of the microbial communities inhabiting the fjord. We have sampled the fjord from head to bottom at 5 and 20 m below sea level over a few seasons to understand changes throughout the year. We are also performing mesocosms experiments to understand microbial community dynamics when challenged with a pulse disturbance of antibiotics.

Microbial composition varies seasonally in the Comau Fjord. Colors indicate phyla according to the legend

We have inferred metagenome-assembled genomes or MAGs (657 bacterial and 20 archaeal) of medium- to high-quality and are now characterizing seasonal changes in composition and diversity. In April 2023, we will conduct a series of mesocosm experiments to test the single or combined effect of eutrophication and antibiotics on the resistance and resilience of microbial communities in the Comau Fjord.

MAGs in the Comau Fjord. Most MAGs belonged to Proteobacteria, Cyanobacteria, Actinobacteriota, and Bacteroidota. Archaea were represented by Thermoplasmatota with members belonging to the Class Poseidonia A and B