AME 66:159-167 (2012)  -  DOI: https://doi.org/10.3354/ame01566

ABSTRACT: Diel variations in the protozoan grazing and viral-mediated mortality of Synechococcus spp. were simultaneously estimated using a modified dilution method in the coastal waters off Taiwan during 4 cruises in summer 2011. During the study period, the abundance of Synechococcus spp. showed a clear diel cycle and ranged from 1.2 × 10⁴ cells ml⁻¹ at 08:00 h to 9.8 × 10⁴ cells ml⁻¹ at midnight. The frequency of dividing cell (FDC) values were highest between afternoon and dusk and decreased to <10% between 20:00 and 08:00 h. Synechococcus spp. specific growth rates varied during the experimental period from 0.025 to 0.033 h⁻¹ and 0.050 to 0.085 h⁻¹ at daytime and nighttime, respectively. Rates of Synechococcus spp. mortality due to nanoflagellate grazing averaged 0.031 h⁻¹ during daytime and 0.041 h⁻¹ at night. The estimated mortality due to viral lysis was between 0.011 and 0.019 h⁻¹ during daytime and between 0.026 and 0.065 h⁻¹ at night. Nanoflagellate grazing was the dominant cause of Synechococcus spp. mortality during daytime; however, mortality from viral lysis and nanoflagellate grazing was more balanced at night.

KEY WORDS: Synechococcus spp. · Modified dilution method · Viruses · Nanoflagellates

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Cite this article as: Tsai AY, Gong GC, Sanders RW, Chiang KP, Huang JK, Chan YF (2012) Viral lysis and nanoflagellate grazing as factors controlling diel variations of Synechococcus spp. summer abundance in coastal waters of Taiwan. Aquat Microb Ecol 66:159-167. https://doi.org/10.3354/ame01566 Export citation Share:    Facebook - - linkedIn