The distribution of cyanomyoviruses was estimated using a quantitative PCR (qPCR) approach that targeted the g20 gene as a proxy for phage. Samples were collected spatially during a > 3000 km transect through the Sargasso Sea and temporally during a gyre-constrained phytoplankton bloom within the southern Pacific Ocean. Cyanomyovirus abundances were lower in the Sargasso Sea than in the southern Pacific Ocean, ranging from 2.75 × 10³ to 5.15 × 10⁴ mL⁻¹ and correlating with the abundance of their potential hosts (Prochlorococcus and Synechococcus). Cyanomyovirus abundance in the southern Pacific Ocean (east of New Zealand) followed Synechococcus host populations in the system: this included a decrease in g20 gene copies (from 4.3 × 105 to 9.6 × 103 mL−1) following the demise of a Synechococcus bloom. When compared with direct counts of viruses, observations suggest that the cyanomyoviruses comprised 0.5 to >25% of the total virus community. We estimated daily lysis rates of 0.2–46% of the standing stock of Synechococcus in the Pacific Ocean compared with c. < 1.0% in the Sargasso Sea. In total, our observations confirm this family of viruses is abundant in marine systems and that they are an important source of cyanobacterial mortality.

Item Type:	Refereed Article
Keywords:	marine, Synechococcus, Prochlorococcus, cyanophage, viruses
Research Division:	Biological Sciences
Research Group:	Ecology
Research Field:	Marine and Estuarine Ecology (incl. Marine Ichthyology)
Objective Division:	Environment
Objective Group:	Climate and Climate Change
Objective Field:	Climate Change Adaptation Measures
Author:	Boyd, PW (Professor Philip Boyd)
ID Code:	95539
Year Published:	2013
Web of Science® Times Cited:	15
Deposited By:	IMAS Research and Education Centre
Deposited On:	2014-10-03
Last Modified:	2014-11-11
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