Salt marshes: role within the Bahía Blanca estuary

BOTTE, S.; NEGRÍN, V.; PRATOLONGO, P.; GONZÁLEZ TRILLA, G.

Perspectives on integrated coastal zone management in South America

IST Press

Lugar: Lisboa; Año: 2008; p. 279 - 288

Two important plant communities exist within estuarine environments: salt-marshes in temperateand warm temperate latitudes, and mangrove swamps on tropical and sub-tropicalcoastlines. These wetlands develop in the intertidal zone, a geomorphic environment that permits both the deposition of fine sediments and the establishment of vegetation, making them ofparticular interest from a biogeochemical point of view. Salt-marshes are the main sites for the dynamic exchange of water, sediment and organic matter between uplands and coastal waters. They can either act as a source or a sink of nutrients and contaminants depending on the current biogeochemical characteristics. Macrophytes have also been shown to play important roles in marsh biogeochemistry through their active and passive circulation of elements. The production of organic matter in these environments is also of great interest because of the formation of detritus by halophytic plants, which may be an important component in the food chain in coastal waters due to high primary production and frequent tidal connection. The Bah´ıa Blanca estuary in Argentina, on the northern limits of Patagonia, is a good case study for evaluating the transference of nutrients, metals and organic matter between the coastal zone and the open sea, because stands of halophytic plants are present, as described in others coastal salt-marshes, which are normally dense and varied. A study of the biogeochemical balances of nutrients, metals and other contaminants which can be modified by an increase or decrease in load would provide an important data base that could be included in dynamic models such as MOHID. Moreover, ecological studies of the roles of salt-marshes would provide information that would assist decision makers in land use planning within these systems, when considering future development (e.g., industrial locations, port facilities, fishery fleet, oil transport, processing and storage, etc).