AME prepress abstract  -  doi: 10.3354/ame01231

ABSTRACT: During the spring of 2005, the production rate of virus-like particles as well as microbial and biogeochemical parameters in the Sargasso Sea and North Atlantic Ocean were investigated as part of a multifaceted North Atlantic Spring Bloom (NASB2005) survey. Here we present data on the spatial variations in virus production rate, abundance, and the infection of microbial host populations, in an attempt to understand the constraint(s) on the rate of virus production and viral abundance. As expected, virus-like particle densities increased from the oligotrophic waters of the Sargasso Sea to the more productive northern Atlantic waters. Additionally, virus production rates increased across the Sargasso Sea transect and correlated with trophic status (chl a concentrations) and secondary (bacterial) productivity in this region. However, no clear pattern of virus production rates could be discerned in waters hosting the North Atlantic Spring Bloom. Results of both parametric and non-parametric analyses demonstrate that virus production rates and viral abundances only correlate well for our observations within the constant “stability” of the Sargasso Sea, but suggest more complex relationships along with a threshold effect guide viral parameters in the North Atlantic. Overall this study highlights the spatial and potentially temporal complexity of constraints on virus production and ultimately on virus function in marine surface waters.