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

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.

Review article: How does glacier discharge affect marine biogeochemistry and primary production in the Arctic?

“…This is perhaps not surprising as different taxonomic groups may respond differently to perturbations from glacier discharge leading to changes in food web dynamics. For example, highly turbid glacial waters have particularly strong negative effects on filter-feeding (Arendt et al, 2011;Fuentes et al, 2016) and phagotrophic organisms (Sommaruga, 2015) and may also lead to reduced viral loads in the water column due to adsorption onto particle surfaces (Maat et al, 2019).…”

Investigation of Sediment-Rich Glacial Meltwater Plumes Using a High-Resolution Multispectral Sensor Mounted on an Unmanned Aerial Vehicle

“…To achieve these goals, during the 2019 austral summer in the Admiralty Bay in West Antarctica, recurrent plumes in front of four glaciers, which differ in shape, dynamics, and geological location, were investigated, and their plume waters were examined. A large glacial sediment discharge has an impact on the salinity and temperature of seawater [4], biodiversity, the productivity as well aswell-being of marine flora and fauna, and, dependent on the latter, land animals and birds [19][20][21][22][23][24][25]. Consequently, changes in polar ecosystems require monitoring.…”

Virus removal by glacier-derived suspended fine sediment in the Arctic

“…Another suggested effect of glacier sediment is the adsorption of viruses to these particles (De Corte et al 2011, Maat et al 2019. Viruses are parasites that use the metabolism of the host to propagate.…”

“…Hence, only little is known on the ecological relevance of virus to sediment adsorption, especially for the rapidly warming polar waters. Only very recently, it was experimentally demonstrated that different virus populations, including an Arctic phycovirus, strongly adsorb to glacier-derived fine-sediment (up to 90%; Maat et al 2019).…”

“…Moreover, the production of progeny virus was strongly delayed in the presence of glacier sediment. By adsorption to sediment particles, the viruses are thus at least temporarily not available for infecting new host cells, and the viruses may even be removed long-term from the system when the sediment settles to the sea floor (Lawrence et al 2002, Maat et al 2019.…”