Nutrient regeneration susceptibility under contrasting sedimentary conditions from the Rio de Janeiro coast, Brazil
- Research areas:
- Year:
- 2016
- Keywords:
- Pore water
- Authors:
-
- Christiene R. L. Matos
- Ursula Mendoza
- Rut Diaz
- Manuel Moreira
- Andre L. Belem
- Édouard Metzger
- Ana Luiza S. Albuquerque
- Wilson Machado
- Journal:
- Marine Pollution Bulletin
- Volume:
- 108
- Number:
- 1–2
- Pages:
- 297 - 302
- ISSN:
- 0025-326X
- BibTex:
- Abstract:
- Abstract Dissolved silicate (DSi), NH4+, NO3− and \{PO43\} − susceptibility to be exchanged between sediment pore waters and overlying waters was evaluated in Jurujuba Sound (JS station) and Coroa Grande Sound (CGS station), southeastern Brazil. Sedimentary elemental (C, N and P) and isotopic (δ13C and δ15N) compositions evidenced stronger anthropogenic fertilization in \{JS\} station. Net NO3− influxes from overlying waters occurred, which was two orders of magnitude higher under the more fertilized condition. This condition resulted in 6–13-times higher net effluxes of NH4+, \{DSi\} and \{PO43\} − to overlying waters. Vertical alternation between production and consumption processes in pore waters contributed for a more limited regeneration in \{CGS\} station. This was associated with diagenetic responses to sedimentary grain size variability in deeper layers and biological disturbance in upper layers. Nearly continuous production of NH4+, \{DSi\} and \{PO43\} − in pore waters implied in intensified susceptibility to remobilization under the eutrophic condition of \{JS\} station.