Sediments from Arctic Tide-Water Glaciers Remove Coastal Marine Viruses and Delay Host Infection.

Douwe Maat,Corina Brussaard,Maarten Prins

doi:10.3390/v11020123

Douwe Maat, Corina Brussaard + Show 1 more

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https://doi.org/10.3390/v11020123

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Abstract

Over the past few decades, the Arctic region has been strongly affected by global warming, leading to increased sea surface temperatures and melting of land and sea ice. Marine terminating (tide-water) glaciers are expected to show higher melting and calving rates, with an increase in the input of fine sediment particles in the coastal marine environment. We experimentally investigated whether marine viruses, which drive microbial interactions and biogeochemical cycling are removed from the water column through adsorption to glacier-delivered fine sediments. Ecologically relevant concentrations of 30, 100 and 200 mg·L−1 sediments were added to filtered lysates of 3 cultured algal viruses and to a natural marine bacterial virus community. Total virus removal increased with sediment concentration whereby the removal rate depended on the virus used (up to 88% for an Arctic algal virus), suggesting a different interaction strength with the sediment. Moreover, we observed that the adsorption of viruses to sediment is a reversible process, and that desorbed viruses are still able to infect their respective hosts. Nonetheless, the addition of sediment to infection experiments with the Arctic prasinovirus MpoV-45T substantially delayed host lysis and the production of progeny viruses. We demonstrate that glacier-derived fine sediments have the potency to alter virus availability and consequently, host population dynamics.

Highlights

Coastal marine systems in the Arctic typically contain high concentrations of suspended sediment particles which enter the water column via melting and calving of tide-water glaciers, and via streams and rivers that originate from melting land ice and snow
Melting tide-water glaciers release large amounts of sediment into Arctic coastal waters, which remain suspended in the water column for extended periods, affecting microbial interactions in the pelagic food web [1,2]
We found that glacier-derived sediments led to substantial losses of algal and bacterial viruses, and that the losses increased with higher sediment load and viral abundance

Summary

Introduction

Coastal marine systems in the Arctic typically contain high concentrations of suspended sediment particles which enter the water column via melting and calving of tide-water glaciers, and via streams and rivers that originate from melting land ice (glaciers) and snow. Glacier-derived sediments contain especially high concentrations of fine clay and silt particles They can remain suspended in the water column for a very long time and extend far off the coast [1,2] Since sediment delivery by the melting and calving of tide-water glaciers is driven by seawater temperature (SST) it shows seasonal dynamics, with most sediment input at the time of highest phytoplankton production and food web activity [2,5,6].

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