title: Marine and giant viruses as indicators of a marine microbial community in a riverine system.
abstract: Viral communities are important for ecosystem function as they are involved in critical biogeochemical cycles and controlling host abundance. This study investigates riverine viral communities around a small rural town that influences local water inputs. Myoviridae, Siphoviridae, Phycodnaviridae, Mimiviridae, Herpesviridae, and Podoviridae were the most abundant families. Viral species upstream and downstream of the town were similar, with Synechoccocus phage, salinus, Prochlorococcus phage, Mimivirus A, and Human herpes 6A virus most abundant, contributing to 4.9-38.2% of average abundance within the metagenomic profiles, with Synechococcus and Prochlorococcus present in metagenomes as the expected hosts for the phage. Overall, the majority of abundant viral species were or were most similar to those of marine origin. At over 60 km to the river mouth, the presence of marine communities provides some support for the Baas-Becking hypothesis "everything is everywhere, but, the environment selects." We conclude marine microbial species may occur more frequently in freshwater systems than previously assumed, and hence may play important roles in some freshwater ecosystems within tens to a hundred kilometers from the sea.
authors: School of Biological Sciences at Flinders University, Adelaide, South Australia, Australia.
authors: Lisa M
authors: LM
authors: Dann
authors: Department of Microbiology, Oregon State University, Corvallis, Oregon, USA.
authors: Stephanie
authors: S
authors: Rosales
authors: School of Computer Science, Engineering and Mathematics, Flinders University, Adelaide, Australia.
authors: Jody
authors: J
authors: McKerral
authors: School of Biological Sciences at Flinders University, Adelaide, South Australia, Australia.
authors: James S
authors: JS
authors: Paterson
authors: School of Biological Sciences at Flinders University, Adelaide, South Australia, Australia.
authors: Renee J
authors: RJ
authors: Smith
authors: Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia.
authors: Thomas C
authors: TC
authors: Jeffries
authors: Land and Water Research Division at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, South Australia, Australia.
authors: Rod L
authors: RL
authors: Oliver
authors: School of Biological Sciences at Flinders University, Adelaide, South Australia, Australia.
authors: James G
authors: JG
authors: Mitchell
mesh_terms: D059001:Aquatic Organisms / Q000302:isolation & purification / Q000821:virology; D005618:Fresh Water / Q000821:virology*; D000072139:Giant Viruses / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D054892:Metagenome / Q000235:genetics; D056186:Metagenomics; D064307:Microbiota; D014871:Water Microbiology
keywords: giant viruses; marine-freshwater transitions; metagenomics; riverine systems; viral ecology; viruses