Estudo do fósforo sedimentar e de suas especiações químicas em dois sistemas costeiros e Plataforma Continental Sudeste (Brasil) e Baía do Almirantado (região antártica) considerando suas relações biogeoquímicas / Study of phosphorus and its chemical speciation in sediments in two coastal environments and southeasterns continental shelf (Brazil) and admiralty Bay (Antarctic region) considering its biogeochemical aspects

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

This work aims to study the total and chemical species of phosphorus in the surface sediments associated to the biogeochemical processes in two estuarine systems, the southeastern continental shelf and Antarctic polar region. Bottom water samples were collected in two seasonal periods (summer-winter) in the estuaries under different degrees of environmental anthorpic impacts. The fraction extraction methodology (SEDEX) applied to obtain the chemical phosphorus species was tested in relation to the certified standards before analyses. The results were reproductive and the extraction efficiency was acceptable. The chemical species concentrations of sedimentary phosphorus in the two estuarine systems showed differences between sectors following the granulometric characteristics, tide influence, redox conditions of the bottom waters as well as anthropic actions revealed by quantitative and qualitative data. A minimum seasonal influence was observed. In the case of eastern continental shelf, high values of organic matter were found in nuclei distribution along the platform in the external stations of Santos and Ilha Grande radials showing a differentiation accompanied by organic phosphorus and C org., fractions. In the other radials high CaCO3 values were observed in the external stations. In the Admiralty Bay the predominant fractions were detrital apatite and authigenic/biogenic apatite, being that organic form was low, linked to low values of organic carbon. The quantification and distribution of P species in the sediments constitute important tools to understand the P and the other nutrient biogeochemical cycles in the sea ecosystems

ASSUNTO(S)

características granulométricas caco3 cns especiação de fósforo sedimentar plataforma continental sudeste região polar antártica. caco3 chemical species of sedimentary p estuaries fósforo sedimentar cns sedimentary phosphorus continental shelf estuários granulometric characteristics polar antarctic region

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