Microbial biomass response to different quantities and sources of organic matter in Brazilian coastal sediments

Autor(es)

Quintana, Cintia O. ^{[1, 2]} ; de Moraes, Paula C. ^[1] ; Yoshinaga, Marcos Y. ^[3] ; Wakeham, Stuart G. ^[4] ; Sumida, Paulo Y. G. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Oceanog, BR-05508120 Sao Paulo - Brazil

^[2] Univ Southern Denmark, Inst Biol, Odense M - Denmark

^[3] Univ Bremen, MARUM, Organ Geochem Grp, D-28359 Bremen - Germany

^[4] Skidaway Inst Oceanog, Savannah, GA - USA

• Tipo de documento: Artigo Científico
• Fonte: MARINE ECOLOGY-AN EVOLUTIONARY PERSPECTIVE; v. 36, n. 3, p. 766-779, SEP 2015.
• Citações Web of Science: 2

Resumo

This study investigates the benthic microbial responses to organic matter (OM) variations in quantity and sources in two shallow water bays (Fortaleza and Ubatuba Bays) on the SE coast of Brazil on six occasions during the year. The pelagic and benthic compartments of the bays were evaluated by: (i) nutrients and chlorophyll a (Chl a) in the water column; (ii) quantity and sources of OM in the sediment (Chl a, total organic carbon and total nitrogen and lipid biomarker composition); and (iii) microbial biomass in sediments as an indicator of active benthic response. Although there were changes in water-column nutrients during the year, Chl a was fairly constant, suggesting a regular supply of microalgae-derived OM to the sea bottom. Based on the composition of lipid biomarkers in sediments, OM sources were classified as mostly marine and with high contributions of labile (microalgae-derived) OM. Labile OM composition varied from diatoms in the summer to phytoflagellates in the winter and tended to accumulate in areas protected by physical disturbances in one of the bays. Microbial biomass followed this trend and was 160% higher in protected than in exposed areas. This study suggests that the coupling between labile OM and benthic microbial biomass occurs primarily in protected areas, irrespective of the time of the year. Since meio- and macrofaunal assemblages depend upon secondary microbial production within the sediments, this coupling may have an important role for the benthic food-web. (AU)

• Processo FAPESP: 12/06121-1 - Vias de degradação da matéria orgânica em sedimentos costeiros marinhos: implicações para o funcionamento do ecossistema (pathways)
• Beneficiário: Cintia Organo Quintana
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 05/57516-2 - Quantificação de bactérias bênticas em duas enseadas de Ubatuba (SP): avaliação da resposta bacteriana ao aporte de matéria orgânica em sedimentos costeiros
• Beneficiário: Paula Carpintero de Moraes
• Linha de fomento: Bolsas no Brasil - Mestrado
• Processo FAPESP: 04/03906-1 - Indicadores moleculares da qualidade na matéria orgânica em sedimentos costeiros: diagênese recente e influência no sistema bêntico
• Beneficiário: Paulo Yukio Gomes Sumida
• Linha de fomento: Auxílio à Pesquisa - Regular
• Processo FAPESP: 04/06369-7 - O aporte da matéria orgânica nos sedimentos da margem continental de Cabo Frio (RJ) e Ubatuba (SP): avaliação da origem, quantidade e qualidade da matéria orgânica disponível à cadeia alimentar bêntica
• Beneficiário: Marcos Yukio Yoshinaga
• Linha de fomento: Bolsas no Brasil - Doutorado Direto