DISTRIBUTION OF THE ORGANIC MATTER, ORGANIC CARBON, ORGANIC NITROGEN AND TOTAL PHOSPHORUS IN RECENT SEDIMENTS OF CONCEPCION BAY

Abstract

Meteorological conditions during spring, summer and early autumn in the Coastal zone of Concepción Bay. are favorable for upwelling. During this period, high valúes of phytoplankton and zooplankton biomass and a high secondary production rate in the benthos have been reponed, for Concepción Bay. There are some evidences suggesting that upwelled Equatorial Subsurface waters may be a principal factor for a surplus oforganic matter production inside the bay. An importara pan of thissurplus production sinks totheboltom where it overlays the soft sediment, producing a reducing environment. This paper reports concentraron data of organic matter, organic carbón, organic nitrogen and total phosphorus in samples from recently deposited sediments in the Concepción Bay. The concentratiqn valúes of organic carbón are high (i.e., 3.5% in the central pan of the Bay) when compared with valúes for other Coastal zones (í.e., 2.0% in the Guayaquil Gulf). However there are lower than those of Walvis Bay in south west Africa (í.r., 25.0% of organic carbón). The spatial distribution of the studied parameters show that: 1) there is an active autogenic process of remineralizaron within the bay, and 2) the organic pollution has a reduced and localized effect.