Interactions of infectious F-specific RNA bacteriophages with suspended matter and sediment: Towards an understanding of FRNAPH distribution in a river water system

Abstract

The association of viruses with settling particles is certainly a major process controlling the spread of viral pollution in surface water and sediment. To better understand the viral distribution in a river system, the behavior of F-specific RNA bacteriophages (FRNAPHs) was investigated in relationship with the suspended solids and sediment. The partitioning of phage particles (free or associated with solids) in surface water and the attachment capabilities of eight distinct strains of phages to sediment were studied in lab experiments. In situ observations were also performed with the genotyping of 166 individual plaques of FRNAPHs isolated from surface water and sediment. The results reported here demonstrate a variation of the status of infectious phages as a function of the hydro-climatological conditions. Phage-solid association seems to mainly occur during the peak of rainfall-runoff events but also to a certain extent during the recession phase compared to low flow conditions. The transfer of phages from the water column to sediment may occur at this time. Furthermore, the ability of FRNAPHs to interact with sediment was established for six strains out of eight, belonging to genogroups II, III and IV. A similar dynamic was observed for strains within a same genogroup despite different intensity of attachment and inactivation rates for strains of genogroups III and IV. The latter results match the in situ observations in the water and sediment compartments of the studied area. Infectious FRNAPH genogroup II was more abundant in sediment than in surface water. Its capability to sorb to sediment and its higher persistence in the environment compared to genogroups III and IV were the two main explanations. Together, lab and in situ experiments produce an overall vision of the mechanisms governing FRNAPH distribution among the water column and riverbed sediment.

The Roles of Suspension-Feeding and Flux-Feeding Zooplankton as Gatekeepers of Particle Flux Into the Mesopelagic Ocean in the Northeast Pacific

“…Instead, their activity leads to near complete consumption of slowly sinking particles near the base of the euphotic zone. This is likely a general result, because studies focused on in situ measurement of particle sinking speeds often find typical velocities on the order of 100 m day −1 beneath the euphotic zone (Alldredge and Gotschalk, 1988;Trull et al, 2008;Armstrong et al, 2009;McDonnell and Buesseler, 2010; FIGURE 9 | Importance of pteropods to flux attenuation. The abundance of Limacina helicina in MOCNESS tows conducted during two cycles on the P1208 cruise from Bednaršek and Ohman (2015) (A).…”

Modeling Environmental DNA Transport in the Coastal Ocean Using Lagrangian Particle Tracking

“…Two possibilities for w s in Equation 1 were considered to represent end-member, extreme values. The first case was that eDNA was neutrally buoyant (w s = 0 cm s −1 ) and the second case was that eDNA was assigned a fast settling rate representative of marine particulates (w s = 0.1 cm s −1 ) determined by in-situ experiments (Alldredge and Gotschalk, 1988).…”

Investigating Particle Size-Flux Relationships and the Biological Pump Across a Range of Plankton Ecosystem States From Coastal to Oligotrophic

“…Since both the mass and sinking speed of a marine snow aggregates can be related to the ESD of the aggregate by power law relationships (Alldredge and Gotschalk, 1988;Alldredge, 1998;Lombard and Kiørboe, 2010), Guidi et al (2008) suggested that total particle mass flux (F [mg C m −2 d −1 ]) can be calculated from the particle size distribution using the equation:…”

“…Most optical approaches rely on a strong covariance between particle size (or a proxy for particle size) and the property of interest, which for carbon export is mass flux. Previous work has demonstrated trends between particle size and sinking velocity (Smayda, 1971;Alldredge and Gotschalk, 1988;Stamieszkin et al, 2015), as well as particle size and mass (Alldredge, 1998). Therefore a reasonable approach was undertaken in Guidi et al (2008) to couple these properties into mass flux for the UVP platform.…”