title: Mussel biofiltration effects on attached bacteria and unicellular eukaryotes in fish-rearing seawater.
abstract: Mussel biofiltration is a widely used approach for the mitigation of aquaculture water. In this study, we investigated the effect of mussel biofiltration on the communities of particle-associated bacteria and unicellular eukaryotes in a sea bass aquaculture in southern North Sea. We assessed the planktonic community changes before and after biofiltration based on the diversity of the 16S and 18S rRNA genes by using next generation sequencing technologies. Although there was no overall reduction in the operational taxonomic units (OTU) numbers between the control (no mussels) and the test (with mussels) tanks, a clear reduction in the relative abundance of the top three most dominant OTUs in every sampling time was observed, ranging between 2-28% and 16-82% for Bacteria and Eukarya, respectively. The bacterial community was dominated by OTUs related to phytoplankton blooms and/or high concentrations of detritus. Among the eukaryotes, several fungal and parasitic groups were found. Their relative abundance in most cases was also reduced from the control to the test tanks; a similar decreasing pattern was also observed for both major higher taxa and functional (trophic) groups. Overall, this study showed the effectiveness of mussel biofiltration on the decrease of microbiota abundance and diversity in seawater fueling fish farms.
authors.affiliation: Laboratoire d'Océanologie et Géosciences (LOG), UMR CNRS 8187, Université du Littoral Côte d' Opale , Wimereux , France.
authors.forename: Eleni
authors.initials: E
authors.lastname: Voudanta
authors.affiliation: Department of Ichthyology & Aquatic Environment, School of Agricultural Sciences, University of Thessaly , Volos , Greece.
authors.forename: Konstantinos Ar
authors.initials: KA
authors.lastname: Kormas
authors.affiliation: Laboratoire d'Océanologie et Géosciences (LOG), UMR CNRS 8187, Université du Littoral Côte d' Opale , Wimereux , France.
authors.forename: Sebastién
authors.initials: S
authors.lastname: Monchy
authors.affiliation: Laboratoire d'Océanologie et Géosciences (LOG), UMR CNRS 8187, Université du Littoral Côte d' Opale , Wimereux , France.
authors.forename: Alice
authors.initials: A
authors.lastname: Delegrange
authors.affiliation: Laboratoire d'Océanologie et Géosciences (LOG), UMR CNRS 8187, Université du Littoral Côte d' Opale , Wimereux , France.
authors.forename: Dorothée
authors.initials: D
authors.lastname: Vincent
authors.affiliation: Laboratoire d'Océanologie et Géosciences (LOG), UMR CNRS 8187, Université du Littoral Côte d' Opale , Wimereux , France.
authors.forename: Savvas
authors.initials: S
authors.lastname: Genitsaris
authors.affiliation: Laboratoire d'Océanologie et Géosciences (LOG), UMR CNRS 8187, Université du Littoral Côte d' Opale , Wimereux , France.
authors.forename: Urania
authors.initials: U
authors.lastname: Christaki
keywords: Bacterial; Biodiversity; Fish farming; Mussel biofiltration; Sea bass; Unicellular eukaryotes