caa a22 4500 60551660X CHVBK 20210128100715.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s10533-015-0094-3 doi (NATIONALLICENCE)springer-10.1007/s10533-015-0094-3 After the flood: changing dissolved organic carbon bioavailability and bacterial growth following inflows to estuaries [Elektronische Daten] [James Hitchcock, Simon Mitrovic] Freshwater inflows play an important role in delivering dissolved organic carbon (DOC) to estuaries. Although considerable DOC can be delivered to estuaries during episodic inflow events, such as floods, little information exists on how the bioavailability of DOC may change during these periods. In this study we used in vitro bioassay incubation experiments to examine how bioavailability changed following inflow events in two temperate south east Australian estuaries; the agricultural Bega River and the forested Clyde River. We measured short-term (2days) and long-term (28days) bioavailable DOC (BDOC) and determined percentage bioavailability, bacterial doubling times (BTd), all with and without excess nitrogen and phosphorus to control for nutrient limitation. Our results showed BDOC varied between 0.13 and 3.62mgCL−1, equivalent to 2.5-31% of initial concentrations. BTd were significantly shorter at the peak of flow and reduced as discharge returned to base flow conditions. Multiple-regression analysis showed discharge and specific ultraviolet light absorbance were the best factors for explaining variance in BDOC whilst discharge was the best factor for explaining BTd. The addition of nutrients led to significantly higher measurements of BDOC and bacteria doubling times on the Clyde River when initial phosphorus concentrations were low. These results highlight the importance of freshwater inflow events as intense moments of biogeochemical transformation in estuaries. Springer International Publishing Switzerland, 2015 Bacteria nationallicence Bioavailability nationallicence Carbon nationallicence Estuary nationallicence River nationallicence Flood nationallicence Hitchcock James Centre for Environmental Sustainability, School of the Environment, University of Technology, Sydney, PO Box 123, 2007, Broadway, NSW, Australia aut Mitrovic Simon Centre for Environmental Sustainability, School of the Environment, University of Technology, Sydney, PO Box 123, 2007, Broadway, NSW, Australia aut Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 219-233 0168-2563 124:1-3<219 2015 124 10533 https://doi.org/10.1007/s10533-015-0094-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-015-0094-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hitchcock James Centre for Environmental Sustainability, School of the Environment, University of Technology, Sydney, PO Box 123, 2007, Broadway, NSW, Australia aut NATIONALLICENCE 700 1- Mitrovic Simon Centre for Environmental Sustainability, School of the Environment, University of Technology, Sydney, PO Box 123, 2007, Broadway, NSW, Australia aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 124/1-3(2015-05-01), 219-233 0168-2563 124:1-3<219 2015 124 10533