%0 Journal Article
%T Bioavailability of Organic Matter in the Superficial Sediment of Guanabara Bay, Rio de Janeiro, Brazil
%A Frederico Sobrinho Silva
%A Jos¨¦ Augusto Pires Bitencourt
%A Fernanda Savergnini
%A Leandro Viana Guerra
%J Anu¨¢rio do Instituto de Geoci¨ºncias
%D 2011
%I Universidade Federal do Rio de Janeiro
%X 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.
%K Biochemical composition
%K sediment
%K bacterial activity
%K organic matter
%K Guanabara Bay
%U http://www.anuario.igeo.ufrj.br/2011_1/2011_1_52_63.pdf