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| Format: | Artículo científico |
| Sprache: | en |
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Universidad Autónoma de Baja California
2008
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| Online-Zugang: | https://www.redalyc.org/articulo.oa?id=48034301 |
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| author | C Magalhães |
| author_facet | C Magalhães |
| contents | Dissolved organic carbon and nitrogen dynamics in the Douro River estuary, Portugal C Magalhães C Teixeira R Teixeira I Azevedo AA Bordalo A Machado Ciencias de la Tierra Douro River estuary dissolved organic carbon Dissolved organic nitrogen Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) are metabolically important in estuaries. Their availability is influenced by organic matter inputs (internal and external) as well as by internal microbial transformations withinthe system. In this study, spatial and seasonal dynamics of DOC and DON were evaluated in the Douro River estuary (Portugal).Monthly surveys were performed from October 2005 to December 2006 along a salinity gradient at three different depths. DOC and DON were calculated by subtracting the respective inorganic components (dissolved inorganic carbon, DIC, and dissolved inorganic nitrogen, DIN) from total dissolved carbon (TDC) and total dissolved nitrogen (TDN). In the Douro River estuary, DIC exhibits a linear and positive distribution as a function of salinity, indicating an input of DIC into the estuary from coastal waters. This pattern of distribution along the salinity gradient was also observed for total particulate matter, since a decreasing trend upstream was observed. In contrast, the results showed a general nonconservative behaviour of DOC along the estuarinetransect during most months. This typical deviation from conservative mixing was mainly associated with sewage DOC sources into the lower and middle estuary. On average, DON concentrations represented 5288% of the TDN. Along the transect, relationships between DIN and DON with salinity were generally conservative, decreasing towards the mouth, highlighting the fluvial source of such nitrogen forms; however, occasional DON sewage loads were registered. Estimated global Douro River watershed exports of DOC and DON to coastal waters yielded values of 420 kg C mֿ² yrֿ¹ and 125 kg N mֿ² yrֿ¹, respectively, which are high when compared with previously predicted levels from global models of DOC and DON export. 2008 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48034301 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.3 Vol.34 |
| format | Artículo científico |
| id | redalyc_48034301 |
| language | en |
| publishDate | 2008 |
| publisher | Universidad Autónoma de Baja California |
| spellingShingle | Dissolved organic carbon and nitrogen dynamics in the Douro River estuary, Portugal C Magalhães Ciencias de la Tierra Douro River estuary dissolved organic carbon Dissolved organic nitrogen Dissolved organic carbon and nitrogen dynamics in the Douro River estuary, Portugal C Magalhães C Teixeira R Teixeira I Azevedo AA Bordalo A Machado Ciencias de la Tierra Douro River estuary dissolved organic carbon Dissolved organic nitrogen Dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) are metabolically important in estuaries. Their availability is influenced by organic matter inputs (internal and external) as well as by internal microbial transformations withinthe system. In this study, spatial and seasonal dynamics of DOC and DON were evaluated in the Douro River estuary (Portugal).Monthly surveys were performed from October 2005 to December 2006 along a salinity gradient at three different depths. DOC and DON were calculated by subtracting the respective inorganic components (dissolved inorganic carbon, DIC, and dissolved inorganic nitrogen, DIN) from total dissolved carbon (TDC) and total dissolved nitrogen (TDN). In the Douro River estuary, DIC exhibits a linear and positive distribution as a function of salinity, indicating an input of DIC into the estuary from coastal waters. This pattern of distribution along the salinity gradient was also observed for total particulate matter, since a decreasing trend upstream was observed. In contrast, the results showed a general nonconservative behaviour of DOC along the estuarinetransect during most months. This typical deviation from conservative mixing was mainly associated with sewage DOC sources into the lower and middle estuary. On average, DON concentrations represented 5288% of the TDN. Along the transect, relationships between DIN and DON with salinity were generally conservative, decreasing towards the mouth, highlighting the fluvial source of such nitrogen forms; however, occasional DON sewage loads were registered. Estimated global Douro River watershed exports of DOC and DON to coastal waters yielded values of 420 kg C mֿ² yrֿ¹ and 125 kg N mֿ² yrֿ¹, respectively, which are high when compared with previously predicted levels from global models of DOC and DON export. 2008 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48034301 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.3 Vol.34 |
| title | Dissolved organic carbon and nitrogen dynamics in the Douro River estuary, Portugal |
| topic | Ciencias de la Tierra Douro River estuary dissolved organic carbon Dissolved organic nitrogen |
| url | https://www.redalyc.org/articulo.oa?id=48034301 |