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

Authors

  • Frederico Sobrinho Silva Universidade Federal do Rio de Janeiro; Instituto de Geociências; Departamento de Geologia; Laboratório de Palinofácies & Fácies Orgânica
  • José Augusto Pires Bitencourt Universidade Federal Fluminense; Departamento de Biologia Marinha; Laboratório de Microbiologia Marinha
  • Fernanda Savergnini Universidade Federal Fluminense; Departamento de Biologia Marinha; Laboratório de Microbiologia Marinha
  • Leandro Viana Guerra Universidade Federal Fluminense; Departamento de Biologia Marinha; Laboratório de Microbiologia Marinha
  • José Antônio Baptista-Neto Universidade Federal Fluminense; Instituto de Geociências; Departamento de Geologia Marinha
  • Mirian Araújo Carlos Crapez Universidade Federal Fluminense; Departamento de Biologia Marinha; Laboratório de Microbiologia Marinha

DOI:

https://doi.org/10.11137/2011_1_52-63

Abstract

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.

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Published

2011-01-01

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