Comparação dos níveis de produtividade na região do mangal e do canal do estuário dos Bons Sinais com base nas concentrações de carbono orgânico, Quelimane - província da Zambézia

Abstract

Based on the records, 58 centimeters of sediment samples were collected in the mangrove zone and 116 centimeters in the water course. The results of the analyzes allowed the identification of small variations in paleoproductivity when comparing the two samples. However, when analyzed independently, a marked variation was observed in the first 38 centimeters in the sediments corresponding to the mangrove zone in relation to those in the water course region. Depending on the concentrations of organic carbon, two phases with different depth intervals were recognized in both regions. The phases of the mangrove region were designated 0-32 centimeters deep as first and 34-58 centimeters as second; 0-58 centimeters and 60-108 centimeters deep for the water course region respectively and the remaining 8 centimeters for the water course region demonstrate the beginning of a new phase with values of organic carbon rising from 0.0150g to 0.0469g. In general, the first phase is characterized by high values of organic carbon, fine sediments of the silt and clay type, and high productivity, as opposed to the second phase characterized by low values of organic carbon and consequently low productivity, which allied with the deposition of thick sediments (sand).