Seasonal dynamics are the major driver of microbial diversity and composition in intensive freshwater aquaculture

Author(s)
Sophi Marmen, Eduard Fadeev, Ashraf Al Ashhab, Ayana Benet-Perelberg, Alon Naor, Hemant J. Patil, Eddie Cytryn, Diti Viner-Mozzini, Assaf Sukenik, Maya Lalzar, Daniel Sher
Abstract

Aquaculture facilities such as fishponds are one of the most anthropogenically impacted freshwater ecosystems. The high fish biomass reared in aquaculture is associated with an intensive input into the water of fish-feed and fish excrements. This nutrients load may affect the microbial community in the water, which in turn can impact the fish health. To determine to what extent aquaculture practices and natural seasonal cycles affect the microbial populations, we characterized the microbiome of an inter-connected aquaculture system at monthly resolution, over 3 years. The system comprised two fishponds, where fish are grown, and an operational water reservoir in which fish are not actively stocked. Clear natural seasonal cycles of temperature and inorganic nutrients concentration, as well as recurring cyanobacterial blooms during summer, were observed in both the fishponds and the reservoir. The structure of the aquatic bacterial communities in the system, characterized using 16S rRNA sequencing, was explained primarily by the natural seasonality, whereas aquaculture-related parameters had only a minor explanatory power. However, the cyanobacterial blooms were characterized by different cyanobacterial clades dominating at each fishpond, possibly in response to distinct nitrogen and phosphate ratios. In turn, nutrient ratios may have been affected by the magnitude of fish feed input. Taken together, our results show that, even in strongly anthropogenically impacted aquatic ecosystems, the structure of bacterial communities is mainly driven by the natural seasonality, with more subtle effects of aquaculture-related factors.

Organisation(s)
Functional and Evolutionary Ecology
External organisation(s)
University of Haifa, Dead Sea and Arava Science Center, Israel Ministry of Agriculture and Rural Development, Agricultural Research Organization (ARO), Israel Oceanographic and Limnological Research
Journal
Frontiers in Microbiology
Volume
12
ISSN
1664-302X
DOI
https://doi.org/10.1101/2021.02.26.433039
Publication date
02-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
106022 Microbiology
Portal url
https://ucris.univie.ac.at/portal/en/publications/seasonal-dynamics-are-the-major-driver-of-microbial-diversity-and-composition-in-intensive-freshwater-aquaculture(3ce9bcd1-2cce-47a3-a6d2-c509b0d9754e).html