A new paper from Van Bonn et al studies the effect of a water change on the bacterial community of an aquarium. Unfortunately, only the abstract is available openly, but it seems pretty cool:
The bacterial community composition and structure of water from an established teleost fish system was examined before, during and after a major water change to explore the impact of such a water-change disturbance on the stability of the aquarium water microbiome. The diversity and evenness of the bacterial community significantly increased following the 90% water replacement. While the change in bacterial community structure was significant, it was slight, and was also weakly correlated with changes in physicochemical parameters. Interestingly there was a significant shift in the correlative network relationships between operational taxonomic units from before to after the water replacement. We suggest this shift in network structure is due to the turnover of many taxa during the course of water replacement. These observations will inform future studies into manipulation of the microbiome by changing system environmental parameter values to optimize resident animal health
Our data from the aquarium microbiome project here at the Eisen lab didn’t show significant community shifts with water changes, but ours were very small water changes (we had no control over them since we were piggybacking off someone else’s aquarium set-up). The biggest perturbation we had to our system was the addition of sand and rocks, so it’s great that someone observed community changes tied to a huge water change!