Oceanographic characteristics of camamu bay (14°s, Brazil) during dry and wet conditions

Abstract

The Camamu bay (BCM), located at central coast of Bahia, is a pristine region which has been the target of oil and gas activities that could put in jeopardy the whole ecosystem in the case of an oil spill. The present study provides a first overview of its oceanographic characteristics based on a comprehensive set of in situ data, which points to a significant temporal variability in the hydrology, a strong marine influence in the dry period and a pronounced runoff signature in the wet season. Depending on the combined effect of the freshwater input and tidal circulation, the main channels of BCM present distinct dynamics. The Maraú channel, in the southern section of the bay, behaves mainly as a partially mixed system, but with spatial variability of the mixing condition. Serinhaém channel, in the northern section of the bay, is well mixed during spring tides and partially mixed during neap tides. The bay mouth is well mixed throughout, both during spring and neap tides. The depuration capability of the bay is seasonally controlled, presenting 90 days and 30 days flushing times for the dry and wet season respectively.