Bioavailability of Organic Matter in the Superficial Sediment of Guanabara Bay, Rio de Janeiro, Brazil

• Autor(a) principal: Silva, Frederico Sobrinho
• Data de Publicação: 2011
• Outros Autores: Bitencourt, José Augusto Pires, Savergnini, Fernanda, Guerra, Leandro Viana, Baptista-Neto, José Antônio, Crapez, Mirian Araújo Carlos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Anuário do Instituto de Geociências (Online)
• Texto Completo: https://revistas.ufrj.br/index.php/aigeo/article/view/6816

Thirty superficial sediment samples were collected in Guanabara Bay in order to identify new trophic state and environmental quality descriptors for coastal systems. A biochemical approach was used for analyzing the quality and quantity of sedimentary organic matter and metabolic bacterial activity. The samples were analyzed for particle size; organic matter, protein, carbohydrate, lipid, biopolymeric carbon, and bioavailable carbon levels; and bacterial metabolic activity. The results show a homogeneous spatial distribution for the anaerobic bacteria web and for biopolymers (carbohydrates>;lipids>;protein). The NE area of the bay displayed sediment lipid levels above 1 mg/g, indicative of organic sewage input. Spatial distribution of the superficial sediments in relation to other variables was not significant (p>;0.05). Biopolymers and labile organic matter showed a significant correlation with the average particle size of 80% of the fine particles. Despite the availability of labile organic matter, under the form of biopolymeric carbon, only 50% of the carbon was available to the trophic web. The bacterial consortia formed by sulfate reducing and denitrifying bacteria sustain the benthic trophic food web in Guanabara Bay.