Microbial production along the West Florida Shelf: Responses of bacteria and viruses to the presence and phase of Karenia brevis blooms

摘要: Abstract Bacterial abundance, production, protein and nucleic acid synthesis, growth, viral abundance were measured in waters associated with three bloom stages of the “red tide” dinoflagellate Karenia brevis along south West Florida Shelf (WFS). Measurements taken: (1) when no was present; (2) during initiation stage a bloom; (3) maintenance bloom. Results indicate that bacterial community nutrient limited non-bloom period, highest production rates occurring near within estuaries. Abundance virus like particles (VLPs) higher estuaries, but we hypothesize VLPs not high source mortality, possibly due to decay UV degradation or extracellular nucleases. High balanced statistically similar bacteria abundances on consecutive days initiating suggest highly productive equally mortality. VLP declined first 48 h both stages, suggesting genomes either host cells (not evident water column samples), mortality mixotrophic grazing by K. . Using conservative rate 1 bacteria  −1  h , could account for >100% an significantly decreased synthesis became unbalanced phase An increase most likely cause as only ∼4% change abundance. Together, these data viruses play critical role formation termination blooms.