{"id":448,"date":"2020-09-28T20:58:26","date_gmt":"2020-09-29T00:58:26","guid":{"rendered":"https:\/\/www2.whoi.edu\/staff\/bvanmooy\/?page_id=448"},"modified":"2020-09-29T17:00:17","modified_gmt":"2020-09-29T21:00:17","slug":"the-convergent-impact-of-marine-viruses-minerals-and-microscale-physics-on-phytoplankton-carbon-sequestration","status":"publish","type":"page","link":"https:\/\/www2.whoi.edu\/staff\/bvanmooy\/the-convergent-impact-of-marine-viruses-minerals-and-microscale-physics-on-phytoplankton-carbon-sequestration\/","title":{"rendered":"The Convergent Impact of Marine Viruses, Minerals, and Microscale Physics on Phytoplankton Carbon Sequestration"},"content":{"rendered":"\n

The Convergent Impact of Marine Viruses, Minerals, and Microscale Physics on Phytoplankton Carbon Sequestration<\/h1>\n

Sinking, aggregated particles of ballasted, marine phytoplankton export carbon from the surface to the \u00a0deep-ocean and play a key role in the oceanic biological pump. Decades of research have provided insight \u00a0into carbon flow through the ocean, but immense spatial and temporal variability in productivity and \u00a0export efficiency remain unexplained. Filling these \u2018gaps\u2019 in the global carbon budget is predicated on a \u00a0holistic approach that incorporates novel conceptual thinking and coordinated analytical measurements \u00a0from distinct fields that have been traditionally studied in isolation. Proposed research converges biology, \u00a0chemistry, physics, engineering, mathematics, and computational modeling at the intersection of two \u00a0paradigms that describe how ecosystem interactions regulate the flow of carbon in the ocean. The \u2018ballast \u00a0hypothesis\u2019 states that the sinking flux of particulate organic matter (POC) is dominated by \u00a0phytoplankton-derived particles containing ballast minerals (coccolithophores containing calcium \u00a0carbonate and diatoms containing biogenic silica), which mechanistically increase particle density and \u00a0sinking velocity. The \u2018virus shunt hypothesis\u2019 states that infection and lysis of phytoplankton releases \u00a0cellular debris and dissolved organic carbon, simultaneously decreasing the mass and velocity of particles \u00a0sinking to depth and enhancing upper ocean respiration. Based on our extensive previous lab- and field- based findings, we posit that there are several, overlooked, ecosystem linkages and microscale physical \u00a0regimes by which viral infection increases POC sinking flux and carbon sequestration to depth. These \u00a0include enhanced particle aggregation, increased ballast production, formation of spores (diatoms), and \u00a0enhanced production of ballasted fecal pellets by zooplankton grazers. We suggest that these dynamic and \u00a0coupled phytoplankton-pathogen-particle-predator linkages, which were traditionally thought to be \u00a0independent and competing, coalesce in certain chemical and physical regimes to facilitate export flux \u00a0and explain the high variability of POC export efficiency.<\/p>\n

Our work fills an urgent need to elucidate and quantify the linkages between viruses and ballast minerals, \u00a0fundamentally altering our understanding of carbon cycling and the impact of viruses within it. Proposed \u00a0research couples laboratory-based experiments on model host-virus-grazer systems with extensive field- based observational and manipulative studies on natural populations of diatoms and coccolithophores, the \u00a0two phytoplankton groups that collectively account for ~98% of the estimated POC flux to the deep \u00a0ocean. Experiments and measurements integrate diagnostic biological and chemical controls on infection \u00a0and particle coagulation theory with microscale physics and grazing to quantify links to each \u00a0hypothesized export mechanism under field-relevant turbulent conditions. Cutting-edge engineering and \u00a0analytical tools will be used to diagnose and track infection dynamics while characterizing and \u00a0quantifying particle aggregation and disaggregation, mineral dissolution, sinking dynamics, grazing rates, \u00a0and fecal pellet production at unprecedented resolution and under well-defined, microscale physical \u00a0regimes. Field campaigns will elucidate the relative efficiency of hypothesized mechanisms in stimulating \u00a0POC export in natural blooms while providing bulk and size-resolved estimates of POC flux.<\/p>\n\t

Funding Agency<\/h3>\n

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Collaborators<\/h3>\n