ABSTRACT
The present study was performed in the northeast portion of the Todosos
Santos Bay, Bahia State, Brazil, an area under influence of the Landulpho
Alves-Mataripe (RLAM) refinery effluents. The aim of this work is to evaluate
the modern sedimentary processes based on grain-size analysis, calcium carbonate
and sedimentary organic matter concentration and behavior considering the
possible effects of the petroleum industry’s refining on these sediments. The
concentrations and variations of the three main constituents of organic matter
(total organic C, total N and organic P), and the resulting elemental ratios
(C/N, C/P and N/P), were studied on a seasonal spatial and temporal scale
(winter 2004 and summer 2005), therefore subsidizing the environmental
analysis, especially in regards to the benthic ecosystem. Fifty samples from
twenty-five sampling stations were collected with a grab sampler. Well sorted
sandy sediments are observed in coastal sampling stations and in the Caboto
channel. The recent deposition of fine sediments was observed especially in the
west and central portions of study area. However, these spots contain the
highest percentages of organic material, which do not present significant
seasonal and spatial variations, revealed by the values of total organic C
which reach values of up to 3.1%, total N (0.01% to 0.15%) and the organic P
contents that reach a maximum of 15.9 μmol·g-1. In general, the
elemental ratios indicated continental organic matter inputs, probably derived
from human activities.