TY - JOUR
T1 - Outside the paradigm of upwelling rias in NW Iberian Peninsula
T2 - Biogeochemical and phytoplankton patterns of a non-upwelling ria
AU - Ospina-Alvarez, Natalia
AU - Varela, Manuel
AU - Doval, María Dolores
AU - Gómez-Gesteira, Moncho
AU - Cervantes-Duarte, Rafael
AU - Prego, Ricardo
PY - 2014/2/1
Y1 - 2014/2/1
N2 - The Atlantic Galician rias show the effect of natural eutrophication during ENACW upwelling episodes when large amounts of nutrients are injected. However, the Cantabrian Galician rias do not appear to be disturbed by upwelling events and it can be hypothesized that eutrophy is not inherent to the Galician rias. This question was tackled regarding the biogeochemical and phytoplankton characteristic in the Ria of Barqueiro, located on the western boundary of the Cantabrian Sea, from January 2008 to January 2009. Thermohaline, PAR and fluorescence profiles, dissolved oxygen, nutrient salts, DOC, DON and chlorophyll concentrations, phytoplankton abundances and primary production were monthly determined in a monitoring station (43°45.509'N-07°39.493'W); moreover, the daily upwelling index information and fluvial contributions from Sor River were considered. Throughout the year only four annual oceanographic periods were observed: spring, summer stratification, autumn and winter, unlike the Atlantic rias, where a long upwelling period occurs with usually outstanding upwelling processes. Nutrient concentrations (a maximum of 6.2μM of nitrate, 0.5μM of nitrite, 2.8μM of ammonium, 0.4μM of phosphate and 5.7μM of silicate), organic matter (98μM of DOC, 14μM of DON, 16.4μM of POC and 2.0μM of PON), Chl-a (1.1μgL-1), primary production (280gCm-2yr-1) and phytoplankton abundance were clearly lower (about half) when compared to those reported for the other rias during upwelling. Diatoms dominated the phytoplankton assemblages especially during spring and autumn blooms. In summer, although the wind conditions were favorable, upwelling was not observed in the Ria and a mixing of diatoms and dinoflagellates co-dominated the phytoplankton community with a lower contribution of diatoms in comparison to the Atlantic rias. The paradigm of natural eutrophication reported for the Galician rias was not observed in the Ria of Barqueiro, which may be classified as an oligo-mesotrophic ria-type, according to its environmental patterns.
AB - The Atlantic Galician rias show the effect of natural eutrophication during ENACW upwelling episodes when large amounts of nutrients are injected. However, the Cantabrian Galician rias do not appear to be disturbed by upwelling events and it can be hypothesized that eutrophy is not inherent to the Galician rias. This question was tackled regarding the biogeochemical and phytoplankton characteristic in the Ria of Barqueiro, located on the western boundary of the Cantabrian Sea, from January 2008 to January 2009. Thermohaline, PAR and fluorescence profiles, dissolved oxygen, nutrient salts, DOC, DON and chlorophyll concentrations, phytoplankton abundances and primary production were monthly determined in a monitoring station (43°45.509'N-07°39.493'W); moreover, the daily upwelling index information and fluvial contributions from Sor River were considered. Throughout the year only four annual oceanographic periods were observed: spring, summer stratification, autumn and winter, unlike the Atlantic rias, where a long upwelling period occurs with usually outstanding upwelling processes. Nutrient concentrations (a maximum of 6.2μM of nitrate, 0.5μM of nitrite, 2.8μM of ammonium, 0.4μM of phosphate and 5.7μM of silicate), organic matter (98μM of DOC, 14μM of DON, 16.4μM of POC and 2.0μM of PON), Chl-a (1.1μgL-1), primary production (280gCm-2yr-1) and phytoplankton abundance were clearly lower (about half) when compared to those reported for the other rias during upwelling. Diatoms dominated the phytoplankton assemblages especially during spring and autumn blooms. In summer, although the wind conditions were favorable, upwelling was not observed in the Ria and a mixing of diatoms and dinoflagellates co-dominated the phytoplankton community with a lower contribution of diatoms in comparison to the Atlantic rias. The paradigm of natural eutrophication reported for the Galician rias was not observed in the Ria of Barqueiro, which may be classified as an oligo-mesotrophic ria-type, according to its environmental patterns.
KW - Nutrients
KW - Oceanography
KW - Phytoplankton
KW - Primary production
KW - Pristine
KW - Spain
KW - Thermohaline
UR - http://www.scopus.com/inward/record.url?scp=84893174252&partnerID=8YFLogxK
U2 - 10.1016/j.ecss.2013.12.003
DO - 10.1016/j.ecss.2013.12.003
M3 - Artículo
SN - 0272-7714
VL - 138
SP - 1
EP - 13
JO - Estuarine, Coastal and Shelf Science
JF - Estuarine, Coastal and Shelf Science
ER -