Sediment Denitrification in Two Contrasting Tropical Shallow Lagoons

Autores

Enrich-Prast, A., Santoro, A.L., Coutinho, R.S., Nielsen, L.P. and Esteves, F.A.

Publicado en

Estuaries and Coasts, v. 39(3):657-663

Año de publicación

2016

Afiliaciones

  • Laboratório de Biogeoquímica, Departamento de Ecologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, (RJ) 21941-971, Brazil
  • Department of Environmental Change, Linköping University, 581, 83 Linköping, Sweden
  • Laboratório de Limnologia, Departamento de Ecologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, (RJ) 21941-971, Brazil
  • Department of Biology, University of Aarhus, Ny Munkegade 114, DK8000 Aarhus C, Denmark
  • Núcleo de Pesquisas em Ecologia e Desenvolvimento Sócio-ambiental de Macaé – NUPEM, Universidade Federal do Rio de Janeiro – UFRJ, Av. Rotary Club, s/n, Macaé, RJ CEP 28970-000, São José do Barreto, Brazil

Programa

CRN3

Proyecto

CRN3038

Keywords

Nitrogen, Denitrification, Oxygen consumption, Sediment, Tropical, Coastal lagoons

DOI

https://doi.org/10.1007/s12237-015-0017-5
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Resumen

Sediment denitrification was monthly evaluated in two tropical coastal lagoons with different trophic states using the 15N isotope pairing technique. Denitrification rates were very low in both environments, always <5.0μmol N2 m-2 h-1and were not significantly different between them. Oxygen consumption varied from 426 to 4248 μmol O2 m-2 h-1 and was generally three times higher in the meso-eutrophic than the oligotrophic lagoon. The low denitrification activity was ascribed to both low water NO3– concentrations (<2.0 μM) and little nitrate supply from nitrification. There was no correlation of denitrification with nitrate or ammonium fluxes. Sediments in temperate environments with similar oxygen consumption rates usually presented a higher proportion of nitrification&ndashdenitrification rates. Sediment oxygen consumption was a good predictor of sediment denitrification in both studied lagoons.