- To initiate research on algal viruses (viruses that infect eukaryotic algae) and cyanophages (viruses that infect cyanobacteria) in the Bay of Quinte, a Lake Ontario embayment, samples of viruses free in the water (i.e. not associated with particulate material) were collected throughout 2011 with the goals of examining the diversity of phytoplankton viruses and monitoring their dynamics.
- PCR and sequencing of DNA polymerase (polB) and major capsid protein (MCP) genes from algal viruses, and sheath protein genes from cyanophages, revealed diverse phytoplankton viruses in the bay. Specifically, polB sequences from the bay were most closely related to sequences from viruses that infect prasinophyte algae, MCP sequences were related to sequences from viruses that infect prasinophytes and from Mimivirus-like viruses that infect prymnesiophytes and prasinophytes, whilst sheath protein sequences were related to sequences from the phage Ma-LMM01 that infects M. aeruginosa.
- The abundances of 10 distinct viral genes monitored using quantitative PCR ranged from exceptionally high values (e.g. 256 441 gene copies mL−1 for a putative M. aeruginosa phage) to values that were just above detection limits (e.g. a putative Prasinovirus never exceeded 20 gene copies mL−1).
- Patterns of abundance included genes that were seasonally sporadic or geographically patchy, as well as some that were stable throughout the bay over the entire year. Despite the heterogeneity of viral abundance across the bay, gene abundance clustered by sampling date and geographical location.
- Even for closely related viruses, seasonality and geographical distribution were distinct. By providing evidence for the complex seasonality of diverse phytoplankton viruses, this work highlighted significant gaps in knowledge of aquatic virus ecology that can be extrapolated from this one system to most aquatic environments.