Metabolism and carbon, oxygen, and nutrient fluxes (DIC, DOC, DO2, NO2 −, NO3 −, NH4 +, PO4 3− and SiO4 4−) were studied during three surveys at two sites (VN1 and VN3) located at a fish farm at theMarano and Grado Lagoon (northern Adriatic Sea), using an in situ benthic chamber. Field experimentswere conducted in July and October 2015 and March 2016 at a depth of approximately 2 m along the main channels of the fish farm.Water samples were collected by a scuba diver every 2 h in order to investigate daily fluxes of solutes across the sediment-water interface (SWI). Regarding the solid phase, Corg/Ntot and Corg/Porg molar ratios suggested an autochthonous marine origin of the organic matter and a minor preservation of P in the sediments, respectively; high values of sulphur (Stot) were also encountered (0.8–2%). The conditions at VN3 were mostly anoxic with high NH4 + levels (30–1027 μM) and the absence of NO3 −. Substantial daily patterns of all solutes occurred especially in autumn andwinter. On the contrary, fluxes at VN1were less pronounced. Usually, inverse correlations appeared between dissolved O2 and DIC trends, but in our systemthis was observed only at VN3 in autumn and accomplished by a parallel increase inNH4 +, PO4 3− and SiO4 4− during intense nutrient regeneration. These results are significantly different than those reported for open lagoon environments,where nutrient regeneration at the SWI and in surface sediments is the primary source of nutrients available for assimilation processes, especially during the warmer period of the year when the natural nutrient input by fresh water inflows is limited. Due to the importance of this site for aquaculture, biodiversity and ecosystem services, useful suggestions have been provided from this study in order to improve the quality of this unique aquatic system.

Benthic nutrient cycling at the sediment-water interface in a lagoon fish farming system (northern Adriatic Sea, Italy).

De Vittor C;
2018

Abstract

Metabolism and carbon, oxygen, and nutrient fluxes (DIC, DOC, DO2, NO2 −, NO3 −, NH4 +, PO4 3− and SiO4 4−) were studied during three surveys at two sites (VN1 and VN3) located at a fish farm at theMarano and Grado Lagoon (northern Adriatic Sea), using an in situ benthic chamber. Field experimentswere conducted in July and October 2015 and March 2016 at a depth of approximately 2 m along the main channels of the fish farm.Water samples were collected by a scuba diver every 2 h in order to investigate daily fluxes of solutes across the sediment-water interface (SWI). Regarding the solid phase, Corg/Ntot and Corg/Porg molar ratios suggested an autochthonous marine origin of the organic matter and a minor preservation of P in the sediments, respectively; high values of sulphur (Stot) were also encountered (0.8–2%). The conditions at VN3 were mostly anoxic with high NH4 + levels (30–1027 μM) and the absence of NO3 −. Substantial daily patterns of all solutes occurred especially in autumn andwinter. On the contrary, fluxes at VN1were less pronounced. Usually, inverse correlations appeared between dissolved O2 and DIC trends, but in our systemthis was observed only at VN3 in autumn and accomplished by a parallel increase inNH4 +, PO4 3− and SiO4 4− during intense nutrient regeneration. These results are significantly different than those reported for open lagoon environments,where nutrient regeneration at the SWI and in surface sediments is the primary source of nutrients available for assimilation processes, especially during the warmer period of the year when the natural nutrient input by fresh water inflows is limited. Due to the importance of this site for aquaculture, biodiversity and ecosystem services, useful suggestions have been provided from this study in order to improve the quality of this unique aquatic system.
File in questo prodotto:
File Dimensione Formato  
petranich et al_Benthic Fluxes_2018.pdf

non disponibili

Tipologia: Altro materiale allegato
Licenza: Non specificato
Dimensione 2.34 MB
Formato Adobe PDF
2.34 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/20.500.14083/1535
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact