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Are viruses important in the plankton of highly turbid glacier-fed lakes?

Drewes F, Peter H, Sommaruga R - Sci Rep (2016)

Bottom Line: In the glacier-fed turbid lakes, VLP abundance increased with distance to the glacier, but the highest numbers were observed in the clear lake by the end of August, coinciding with the maximum in prokaryotic abundance.Our results suggest that viral loss by attachment to particles is less important than expected.Nevertheless, the relatively lower variability in VLP abundance and the lower virus-to-prokaryote ratio found in the turbid lakes than in the clear one point to a rather low temporal turnover and thus, to a reduced impact on microbial communities.

View Article: PubMed Central - PubMed

Affiliation: University of Innsbruck, Institute of Ecology, Lake and Glacier Research Group, Technikerstr. 25, 6020 Innsbruck, Austria.

ABSTRACT
Viruses are ubiquitous in aquatic ecosystems where they significantly contribute to microbial mortality. In glacier-fed turbid lakes, however, viruses not only encounter low host abundances, but also a high number of suspended mineral particles introduced by glacier meltwaters. We hypothesized that these particles potentially lead to unspecific adsorption and removal of free virus from the plankton, and thus significantly reduce their abundance in this type of lake. We followed the distribution of free virus-like particles (VLP) during the ice-free season across a turbidity gradient in four alpine lakes including one adjacent clear system where hydrological connectivity to the receding glacier is already lost. In the glacier-fed turbid lakes, VLP abundance increased with distance to the glacier, but the highest numbers were observed in the clear lake by the end of August, coinciding with the maximum in prokaryotic abundance. Our results suggest that viral loss by attachment to particles is less important than expected. Nevertheless, the relatively lower variability in VLP abundance and the lower virus-to-prokaryote ratio found in the turbid lakes than in the clear one point to a rather low temporal turnover and thus, to a reduced impact on microbial communities.

No MeSH data available.


Related in: MedlinePlus

Faselfad catchment showing the three turbid lakes FAS 1 (2600 m a.s.l.), FAS 3 (2400 m a.s.l), and FAS 6 (2200 m a.s.l.), as well as the clear lake FAS4 (2400 m a.s.l.).FAS 1 and FAS 3 are connected with a stream, however, depending on time of the year this stream flows partially below surface. FAS 4 and FAS 6 are also connected by a partially subsurface stream. Orthophotograph source: http://www.tirol.gv.at/tiris.
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f1: Faselfad catchment showing the three turbid lakes FAS 1 (2600 m a.s.l.), FAS 3 (2400 m a.s.l), and FAS 6 (2200 m a.s.l.), as well as the clear lake FAS4 (2400 m a.s.l.).FAS 1 and FAS 3 are connected with a stream, however, depending on time of the year this stream flows partially below surface. FAS 4 and FAS 6 are also connected by a partially subsurface stream. Orthophotograph source: http://www.tirol.gv.at/tiris.

Mentions: In this study, we assess the occurrence and distribution of VLP during the ice-free season in four lakes representing a turbidity gradient and discuss the abiotic and biotic parameters that may regulate their abundance. The four lakes known as Faselfad (hereafter abbreviated as FAS, Fig. 1) have formed due to the retreat of a mountain glacier111216. Three of the lakes (FAS 1, 3, and 6) are hydrologically connected to the rapidly receding glacier and are turbid (Fig. 1). The fourth lake (FAS 4) has lost its hydrological connectivity with the glacier and is now clear. The lakes are situated along an altitudinal gradient, which also represents the sequence of lake formation, FAS1 being the youngest system.


Are viruses important in the plankton of highly turbid glacier-fed lakes?

Drewes F, Peter H, Sommaruga R - Sci Rep (2016)

Faselfad catchment showing the three turbid lakes FAS 1 (2600 m a.s.l.), FAS 3 (2400 m a.s.l), and FAS 6 (2200 m a.s.l.), as well as the clear lake FAS4 (2400 m a.s.l.).FAS 1 and FAS 3 are connected with a stream, however, depending on time of the year this stream flows partially below surface. FAS 4 and FAS 6 are also connected by a partially subsurface stream. Orthophotograph source: http://www.tirol.gv.at/tiris.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837353&req=5

f1: Faselfad catchment showing the three turbid lakes FAS 1 (2600 m a.s.l.), FAS 3 (2400 m a.s.l), and FAS 6 (2200 m a.s.l.), as well as the clear lake FAS4 (2400 m a.s.l.).FAS 1 and FAS 3 are connected with a stream, however, depending on time of the year this stream flows partially below surface. FAS 4 and FAS 6 are also connected by a partially subsurface stream. Orthophotograph source: http://www.tirol.gv.at/tiris.
Mentions: In this study, we assess the occurrence and distribution of VLP during the ice-free season in four lakes representing a turbidity gradient and discuss the abiotic and biotic parameters that may regulate their abundance. The four lakes known as Faselfad (hereafter abbreviated as FAS, Fig. 1) have formed due to the retreat of a mountain glacier111216. Three of the lakes (FAS 1, 3, and 6) are hydrologically connected to the rapidly receding glacier and are turbid (Fig. 1). The fourth lake (FAS 4) has lost its hydrological connectivity with the glacier and is now clear. The lakes are situated along an altitudinal gradient, which also represents the sequence of lake formation, FAS1 being the youngest system.

Bottom Line: In the glacier-fed turbid lakes, VLP abundance increased with distance to the glacier, but the highest numbers were observed in the clear lake by the end of August, coinciding with the maximum in prokaryotic abundance.Our results suggest that viral loss by attachment to particles is less important than expected.Nevertheless, the relatively lower variability in VLP abundance and the lower virus-to-prokaryote ratio found in the turbid lakes than in the clear one point to a rather low temporal turnover and thus, to a reduced impact on microbial communities.

View Article: PubMed Central - PubMed

Affiliation: University of Innsbruck, Institute of Ecology, Lake and Glacier Research Group, Technikerstr. 25, 6020 Innsbruck, Austria.

ABSTRACT
Viruses are ubiquitous in aquatic ecosystems where they significantly contribute to microbial mortality. In glacier-fed turbid lakes, however, viruses not only encounter low host abundances, but also a high number of suspended mineral particles introduced by glacier meltwaters. We hypothesized that these particles potentially lead to unspecific adsorption and removal of free virus from the plankton, and thus significantly reduce their abundance in this type of lake. We followed the distribution of free virus-like particles (VLP) during the ice-free season across a turbidity gradient in four alpine lakes including one adjacent clear system where hydrological connectivity to the receding glacier is already lost. In the glacier-fed turbid lakes, VLP abundance increased with distance to the glacier, but the highest numbers were observed in the clear lake by the end of August, coinciding with the maximum in prokaryotic abundance. Our results suggest that viral loss by attachment to particles is less important than expected. Nevertheless, the relatively lower variability in VLP abundance and the lower virus-to-prokaryote ratio found in the turbid lakes than in the clear one point to a rather low temporal turnover and thus, to a reduced impact on microbial communities.

No MeSH data available.


Related in: MedlinePlus