|Is bacterioplankton production in the Ria de Aveiro influenced by salt marshes and bed sediment?|
Almeida, M.A.; Cunha, M.A.; Alcântara, F. (2002). Is bacterioplankton production in the Ria de Aveiro influenced by salt marshes and bed sediment? Aquat. Ecol. 36(4): 469-482
In: Aquatic Ecology. Springer: Dordrecht; London; Boston. ISSN 1386-2588, more
|Authors|| || Top |
- Almeida, M.A.
- Cunha, M.A.
- Alcântara, F.
The contribution of potential export of materials from bottom sediments and salt marshes into the water column of a shallow estuarine system of Ria de Aveiro to the observed high bacterial productivity in the mid section of this estuary was evaluated. Vertical profiles of physical, chemical and bacterial variables were studied in the marine and brackish water zones, and of transversal profiles in the brackish zone only. Although the concentrations of seston (17-241 mg l-1), particulate organic carbon (3-15.5 mg l-1) and chlorophyll (1.2-7.0 μg l-1) varied widely, the vertical and transversal profiles were without much variation. Total bacterial number (0.2-8.5 × 109 cells l-1) and the number of particle-attached bacteria (0.02-2.50 × 109 cells l-1) along vertical and transversal profiles did not differ much, but the rate of bacterial production (0.05-14.2 μg C l-1 h-1) and dissolved organic carbon concentration (6.0-69.2 mg l-1) were frequently higher near the salt marsh margin at the brackish water transect. The increase in productivity could not be associated with runoff of particulate matter but coincided with the inputs of dissolved organic carbon. The results of vertical and transversal profiles point to a minor role of particulate matter additions from the salt marsh area or from bed sediments.