Tidal time-scale variation of inorganic nutrients and organic matter in Bahia Blanca mesotidal estuary, Argentina

MARCOVECCHIO JORGE EDUARDO; SPETTER CARLA VANESA; BOTTÉ SANDRA ELIZABETH; DELUCCHI FEDERICO; ARIAS ANDRÉS HUGO; FERNÁNDEZ SEVERINI MELISA DAIANA; NEGRÍN VANESA; POPOVICH CECILIA ANGELINES; FREIJE RUBEN HUGO

CHEMISTRY AND ECOLOGY

Taylor and Francis

Lugar: Abingdon; Año: 2009 vol. 25 p. 453 - 465

0275-7540

Land-derived materials are regulated by coastal and shelf environmental conditions before being transported to the open sea. It is of great concern to understand the processes and to establish the extent in which they modify terrestrial compound fluxes, such as nutrients, that end up in the oceans. At present, one of the topics that arises the highest interest within environmental coastal studies is the direction and magnitude of inorganic nutrients and the exchange fluxes of organic matter, between the water column and the associated tidal plains, during dairy tidal cycle. These processes, together with the local hydrographic conditions, define the key role of this type of environment: its functioning as nutrient and organic matter reservoir and/or as a source. A research program directed to understand this mechanism within mesotidal estuaries was developed in Bahía Blanca estuary, on the coast of Buenos Aires Province (Argentina).On a tidal time-scale basis, levels of DIN (nitrate + nitrite + ammonium), DIP, DISi, and organic matter were measured in the estuarine water column and tidal plain porewater, for two years. Results showed no significant variations during the tidal cycle, even though the temporal variation of these compounds was clearly identified. In addition, the biological production of the estuary was considered and taken into account to understand the organic matter cycle within the system. Particular conditions of the environment (sediment characteristics, porewater chemical environment, hydrodynamics, anthropogenic sources, etc) were also considered to fully understand the results.