The study of bacteria in aquatic systems, such as fresh or salt water systems, is known as aquatic microbiology. Microscopic plants, animals, bacteria, viruses, and fungus, as well as their behaviour and interactions with other creatures in the aquatic environment, are covered. Aquatic Microbiology is dedicated to the advancement of microbial research in aqueous environments, with an emphasis on freshwater, estuarine, and oceanic ecosystems. Aquatic microbes have a variety of roles in ecosystems and are essential to the biogeochemical cycles on the planet. Aquatic microorganisms are also genetically, physiologically, and environmentally varied, with a wide range of evolutionary, adaptive, and physiological responses.
Microorganisms (bacteria, archaea, viruses, and microbial eukaryotes) in the marine environment, including their biodiversity, ecology, and biogeochemistry, are studied in marine microbiology. The application of metagenomics in revealing the number and composition of marine microbial ecosystems has been crucial. Microorganisms are thought to make up between 70% to 90% of the biomass in the water. They make up the marine microbiome when combined. This microbiome has evolved different life styles and adaptations over billions of years, and it now participates in the global cycling of practically all chemical elements. Microorganisms, which function as decomposers, are essential for nutrient recycling in ecosystems. They're also responsible for almost all photosynthesis in the ocean, as well as carbon, nitrogen, phosphorus, and other nutrients and trace elements cycling.