Microbiome Dynamics in a Large Artificial Seawater Aquarium

Area of Science:

• Microbial ecology
• Aquatic microbiology
• Bioinformatics

Background:

• Artificial habitats like aquariums house numerous animals and have societal value.
• The ecological roles of microbiomes in artificial habitats are not well understood.
• Georgia Aquarium's Ocean Voyager (OV) exhibit is a large, closed-system aquatic habitat mimicking the open ocean.

Purpose of the Study:

• To characterize the water column microbiome of the OV exhibit over 14 months.
• To compare the OV microbiome's stability and composition to natural marine environments.
• To investigate microbial adaptations and their potential impact on animal health in closed systems.

Main Methods:

• 14-month time-series sampling of the OV water column.
• Microbiome composition analysis using metagenomic sequencing.
• Genome assembly and analysis of dominant microbial taxa (MAGs).
• Transcript mapping to identify active genes and metabolic pathways.

Main Results:

• The OV microbiome composition shifted dramatically over short periods, unlike stable natural environments.
• Bloom events occurred, with specific heterotrophic bacterial lineages dominating.
• Dominant bacteria possessed unique genes for cyanophycin synthesis/degradation and plasmid-associated sequences, indicating adaptation.
• Microbiome dynamics were observed despite stable physical and chemical water parameters.

Conclusions:

• Aquarium microbiomes can be highly dynamic, even with stable environmental conditions.
• Unique microbial adaptations may influence ecosystem function in artificial habitats.
• Understanding microbiome fluctuations is crucial for managing animal health in closed aquaculture systems.