wAbstract
@The organic carbon, phosphorus and nitrogen content of silt and
clay fractions of surface sediments from the marine-coastal region
north and south of the Paria Peninsula (PP) were quantified. Organic
carbon concentrations (Corg) were determined
by dry combustion after decarbonation with 10% hydrochloric acid,
and total phosphorus (TP) and total nitrogen (TN). This information
was then used to produce maps of the iso-concentrations of the
distribution of these elements in the sub-marine continental shelf
north of the PP and in the Gulf of Paria (GP). In the silt fraction,
the Corg concentration, TP and TN showed
average values of 1.53, 0.04 and 0.03 %, respectively. The highest
Corg, PT and NT values were recorded from
silts from the PP with a gradual increase towards the west and
the lowest figures were found in the GP. In the clay fraction,
Corg, TN and TP had mean values of 1.64,
0.13 and 0.04 %, respectively, and showed a spatial distribution
very similar to the silt fraction, indicating the influence of
ocean currents and coastal upwelling patterns. The C/N ratio had
an average of 23.67 and showed that the Corg
present in the PP sediments is of marine origin, resulting from
primary productivity, especially towards the west. This zone has
been identified as the most productive in this region due to coastal
upwelling and the influence of the Orinoco and Amazon rivers (Gomez
1996; Monente 1997). In contrast, a greater variability in the
parameters measured was found in the GP sediments, probably due
to the mixing of marine and continental Corg,
confirming the influence of the Orinoco and Amazon waters brought
by the Guyana Current.
Keywords: Marine sediments; Organic carbon; Nitrogen; Phosphorus;
Organic matterx
Introduction
Materials and methods
Results and discussion
@Bathymetry, temperature, dissolved oxygen and fluorescence
indicators in the bottom waters
@Texture
@Organic carbon (Corg)
@Total phosphorus and nitrogen
@C/N ratio
Conclusions
Acknowledgments
References