Fluxes of bacterioplankton between a tidal estuary and the sea: returning to the "Outwelling Hypothesis"

摘要: The tidal dynamics of bacterioplankton communities at the outer part ofa shallow estuary (Ria de Aveiro, Portugal) were studied during 6 cyclesat a fixed sampling site. Bacterial numbers (0.2–8.1 ×109 cells l−1), aminopeptidase activity(189–1662 nmol l−1 h−1),β-glucosidase activity (1.7–67.0 nmoll−1 h−1) and potential glucoseincorporation (0.48–3.99 followed consistent patternof increase ebb decrease flood.Fluxes populations associated heterotrophic activitiesbetween coastal area cycle estimatedfrom water flux as derived from two-dimensional vertically-integratednumerical model. net fluxes estimated for ranged from−26.0 to −2.5 × 1016 bacterial cells. nettidal activities −10 to−80 mol h−1 aminopeptidase, −0.33to −1.10 β-glucosidase and−0.18 +0.03 glucoseincorporation. Net generally negative in sign indicating thetransfer phyto- bacterioplankton, well capacities thedegradation recycling organic matter, estuarinecompartment sea.