A dilution technique for the direct measurement of viral production: a comparison in stratified and tidally mixed coastal waters

Microb Ecol. 2002 Jan;43(1):168-73. doi: 10.1007/s00248-001-1021-9. Epub 2002 Jan 23.


The abundance of heterotrophic bacteria and viruses, as well as rates of viral production and virus-mediated mortality, were measured in Discovery Passage and the Strait of Georgia (British Columbia, Canada) along a gradient of tidal mixing ranging from well mixed to stratified. The abundances of bacteria and viruses were approximately 10(6) and 10(7) mL(-1), respectively, independent of mixing regime. Viral production estimates, monitored by a dilution technique, demonstrated that new viruses were produced at rates of 10(6) and 10(7) mL(-1)h(-1) across the different mixing regimes. Using an estimated burst size of 50 viruses per lytic event, ca. 19 to 27% of the standing stock of bacteria at the stratified stations and 46 to 137% at the deep-mixed stations were removed by viruses. The results suggest that mixing of stratified waters during tidal exchange enhances virus-mediated bacterial lysis. Consequently, viral lysis recycled a greater proportion of the organic carbon required for bacterial growth under non-steady-state compared to steady-state conditions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacteria*
  • Population Dynamics
  • Viruses*
  • Water Microbiology*
  • Water Movements