scholarly journals The influence of the Guadalquivir river on spatio-temporal variability in the pelagic ecosystem of the eastern Gulf of Cádiz

2014 ◽  
Vol 15 (4) ◽  
pp. 721 ◽  
Author(s):  
I. CABALLERO ◽  
E. P. MORRIS ◽  
L. PIETRO ◽  
G. NAVARRO
Keyword(s):  
Temporal Variability ◽  
Phytoplankton Biomass ◽  
Phytoplankton Bloom ◽  
Light Limitation ◽  
Gulf Of Cadiz ◽  
Phytoplankton Blooms ◽  
Pelagic Ecosystem ◽  
Guadalquivir Estuary ◽  
Gulf Of Cádiz ◽  
Spatio Temporal

This study examines the spatio-temporal variability of the turbidity plume and phytoplankton biomass (in terms of chlorophyll) in the marine region influenced by the Guadalquivir estuary using ocean colour images over a period of 11 years (2003-2013). The area of the turbidity plume was calculated using water-leaving radiance at 555 nm (nLw555). Climatologic and monthly averages showed recurrent high nLw555 levels in winter and high chlorophyll in spring. Similar variability was confirmed by Empirical Orthogonal Function (EOF) analysis of 8-day composite images, illustrating the existence of different regions with similar behavior. The first EOF mode explained 60.7% and 31% of the variability in nLw555 and chlorophyll, respectively, and was associated with enhanced Total Suspended Solids (TSS) in autumn-winter and phytoplankton blooms in winter-spring periods. The results confirmed that the development of the turbidity plume and subsequent phytoplankton blooms were strongly regulated by river discharges and precipitation. Indeed, interannual variation in nLw555 was consistent with changes in the large-scale climate index, the North Atlantic Oscillation, a proxy for regional rainfall patterns. In the case of phytoplankton biomass, the second EOF mode revealed differentiation between offshore and nearshore areas, the latter characterized by delayed development of phytoplankton bloom due to light limitation by high TSS. This suggests that the stability of the water column, via its influence on phytoplankton light-limitation, influenced also the timing and magnitude of phytoplankton bloom events. The dynamic of the Guadalquivir estuary turbidity plume is a crucial factor for the pelagic ecosystem of the Eastern Gulf of Cadiz, governing phytoplankton productivity.

scholarly journals Tidal and seasonal carbon and nutrient dynamics of the Guadalquivir estuary and the Bay of Cádiz (SW Iberian Peninsula)

2013 ◽  
Vol 10 (7) ◽  
pp. 4481-4491 ◽  
Author(s):  
M. Ribas-Ribas ◽  
E. Anfuso ◽  
A. Gómez-Parra ◽  
J. M. Forja
Keyword(s):  
Continental Shelf ◽  
Nutrient Dynamics ◽  
Diurnal Changes ◽  
Gulf Of Cadiz ◽  
Mean Velocity ◽  
Guadalquivir Estuary ◽  
Gulf Of Cádiz ◽  
The Mean ◽  
Bay Of Cadiz ◽  
Bay Of Cádiz

Abstract. To study the effects of the physical environment on carbon and nutrient cycle dynamics on the north-eastern shelf of the Gulf of Cádiz, changes in currents, tides, salinity, temperature, carbon system parameters (fugacity of CO2 (fCO2), dissolved organic carbon, dissolved inorganic carbon (DIC) and pH) and other related parameters(dissolved oxygen, total dissolved nitrogen (TDN), nutrients and suspended particulate matter) were measured in transects across the Guadalquivir estuary and Bay of Cádiz mouths. The main objective of this study is to investigate the influence of these inner ecosystems on the carbon and nutrient distributions on the adjacent continental shelf. Three cruises were undertaken in June 2006, November 2006 and February 2007. During the whole study period, Guadalquivir estuary exported components at a rate of 3 Gmol of SiO2, 4 Gmol of DIN, 3 Gmol of TDN, 31 Gmol of DOC and 604 Gmol of DIC per year. On the other hand, Bay of Cádiz imported 3 Gmol of SiO2, 1 Gmol of DIN, 2 Gmol of TDN, 33 Gmol of DOC and 562 Gmol of DIC per year. Diurnal variability of fCO2 could have a potentially important implication on the estimate of air–sea CO2 fluxes. Tides influence velocity and transport of carbon and nutrients: we found statistically significant differences (p < 0.0001, n = 220) between the flood tide (the mean velocity was 4.85 cm s–1) and the ebb tide (the mean velocity was −5.67 cm s–1). Biological activity and diurnal changes have also an important role on the carbon and nutrient dynamics. Seasonal carbon and nutrient variations were found. During June, both systems were exporting components to the adjacent continental shelf of the Gulf of Cádiz, whereas in February both systems were importing. Monthly studies should be undertaken to completely understand this dynamic system.

scholarly journals Tidal and seasonal carbon and nutrients dynamics of the Guadalquivir Estuary and the Bay of Cádiz (SW Iberian Peninsula)

2012 ◽  
Vol 9 (10) ◽  
pp. 14537-14558
Author(s):  
M. Ribas-Ribas ◽  
L. I. Carracedo ◽  
E. Anfuso ◽  
J. M. Forja
Keyword(s):  
Continental Shelf ◽  
Dissolved Inorganic Carbon ◽  
Gulf Of Cadiz ◽  
Diurnal Variability ◽  
Guadalquivir Estuary ◽  
The North ◽  
Total Dissolved Nitrogen ◽  
Gulf Of Cádiz ◽  
Bay Of Cadiz ◽  
Bay Of Cádiz

Abstract. To study the effects of the physical environment on carbon and nutrients cycles dynamics in the north eastern shelf of the Gulf of Cádiz, changes in currents, tides, salinity, temperature, carbon system parameters (fugacity of CO2 (fCO2), dissolved organic carbon, dissolved inorganic carbon and pH) and others related (dissolved oxygen, total dissolved nitrogen, nutrients and suspended particulate matter) were measured in transects across the Guadalquivir Estuary and Bay of Cádiz mouths. Thus, the main objective of this study is to investigate the influence of these inner ecosystems on the carbon and nutrient distributions in the adjacent continental shelf. Three cruises have been undertaken in June 2006, November 2006 and February 2007, each one covering one complete tidal cycle during June, both systems were exporting components to the adjacent continental shelf of the Gulf of Cádiz. In an annual scale, Guadalquivir Estuary exported components while Bay of Cádiz imported them. Diurnal variability of fCO2 could have a potentially important implication on the estimate of air-sea CO2 fluxes. Monthly studies should be undertaken to completely understand this dynamic system.

scholarly journals Geographic variability of sardine dynamics in the Iberian Biscay region

2009 ◽  
Vol 66 (3) ◽  
pp. 495-508 ◽  
Author(s):  
A. Silva ◽  
D. W. Skagen ◽  
A. Uriarte ◽  
J. Massé ◽  
M. B. Santos ◽  
...  
Keyword(s):  
Bay Of Biscay ◽  
Geographic Variability ◽  
Gulf Of Cadiz ◽  
Migration Routes ◽  
Gulf Of Cádiz ◽  
Multiple Regression Models ◽  
Acoustic Surveys ◽  
Disaggregated Data ◽  
Geographic Differences ◽  
Spatio Temporal

Abstract Silva, A., Skagen, D. W., Uriarte, A., Massé, J., Santos, M. B., Marques, V., Carrera, P., Beillois, P., Pestana, G., Porteiro, C., and Stratoudakis, Y. 2009. Geographic variability of sardine dynamics in the Iberian Biscay region. – ICES Journal of Marine Science, 66: 495–508. The spatio-temporal variability in the distribution, demographic structure, recruitment, and mortality of sardine within the Iberian Biscay region is described using area-disaggregated data collected during acoustic surveys and at ports since the mid-1980s. Multiple regression models were used to describe log numbers-at-age obtained annually in ten areas covered by three surveys to test the existence of geographic differences in selectivity-at-age, recruitment strength, and mortality and to infer plausible migration routes. Within Iberian waters, sardine biomass was mainly concentrated off western Portugal and the Gulf of Cadiz. In the Bay of Biscay, biomass levels were comparable with those off western Portugal. Recruitment was localized in a few areas (northern Portugal and the Gulf of Cadiz and Bay of Biscay), intermingling with areas dominated by older fish. Recruitment was generally asynchronous among areas, although some recruitment peaks were noticeable across wider regions. Spatial patterns related to strong and weak year classes and year-class slopes were also noted. Clearly distinct dynamics were not evidenced within the Atlanto–Iberian sardine stock area, but the validity of the northern limit was questioned by the connection between sardine dynamics in the Bay of Biscay and the Cantabrian Sea. The results provided some evidence consistent with the hypothesis of sardine movement from recruiting grounds to areas farther along the coast as they grow.

scholarly journals <i>p</i>CO<sub>2</sub> variability in the surface waters of the eastern Gulf of Cádiz (SW Iberian Peninsula)

Ocean Science ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 1225-1245 ◽  
Author(s):  
Dolores Jiménez-López ◽  
Ana Sierra ◽  
Teodora Ortega ◽  
Soledad Garrido ◽  
Nerea Hernández-Puyuelo ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Surface Waters ◽  
Temporal Variations ◽  
Mean Value ◽  
Gulf Of Cadiz ◽  
Partial Pressure Of Co2 ◽  
Gulf Of Cádiz ◽  
Eastern Shelf ◽  
Spatio Temporal ◽  
Guadalquivir River

Abstract. Spatio-temporal variations in the partial pressure of CO2 (pCO2) were studied during eight oceanographic cruises conducted between March 2014 and February 2016 in surface waters of the eastern shelf of the Gulf of Cádiz (SW Iberian Peninsula) between the Guadalquivir river and Cape Trafalgar. pCO2 presents a range of variation between 320.6 and 513.6 µatm with highest values during summer and autumn and lowest during spring and winter. For the whole study, pCO2 shows a linear dependence with temperature, and spatially there is a general decrease from coastal to offshore stations associated with continental inputs and an increase in the zones deeper than 400 m related to the influence of the eastward branch of the Azores Current. The study area acts as a source of CO2 to the atmosphere during summer and autumn and as a sink in spring and winter with a mean value for the study period of -0.18±1.32 mmol m−2 d−1. In the Guadalquivir and Sancti Petri transects, the CO2 fluxes decrease towards offshore, whereas in the Trafalgar transect fluxes increase due to the presence of an upwelling. The annual uptake capacity of CO2 in the Gulf of Cádiz is 4.1 Gg C yr−1.

scholarly journals Inferring deglacial ventilation ages in Western Mediterranean waters using cold-water corals

2020 ◽  
Author(s):  
Maria de la Fuente ◽  
Luke Skinner ◽  
Gemma Ercilla ◽  
Elia d'Acremont ◽  
Luis Somoza ◽  
...  
Keyword(s):  
Trace Element ◽  
Cold Water ◽  
Western Mediterranean ◽  
Intermediate Water ◽  
Gulf Of Cadiz ◽  
Strait Of Gibraltar ◽  
Gulf Of Cádiz ◽  
The Mediterranean ◽  
Spatio Temporal ◽  
Reservoir Age

&lt;p&gt;Mediterranean Outflow Water (MOW) acts as a net source of salt and heat into North Atlantic intermediate depths that ultimately contributes to the Atlantic Meridional Overturning Circulation. On this basis, it has been hypothesised that MOW variability might influence global climate. Although several studies have documented major glacial-interglacial changes in deep- and intermediate Mediterranean circulation patterns, little is known about associated impacts on MOW properties, in particular its residence time and geochemical signature. Using a set of cold-water coral samples from along the &amp;#8216;pre-MOW&amp;#8217; and MOW path, i.e. from the Alboran Sea to the northern Galician Bank including the Strait of Gibraltar and the Gulf of Cadiz, we aim to identify changes in both the ventilation state of the water masses flowing out of the Mediterranean and the distribution of coral growth.With this purpose, paired Uranium-series and AMS radiocarbon ages have been obtained in the same coral samples allowing any potential change in the reservoir age to be inferred accurately, as well as allowing a spatio-temporal &amp;#8216;coral map&amp;#8217; to be created. Furthermore, these results have been complemented by trace element measurements in benthic foraminifera from the Alboran coral mound sediment core.&lt;/p&gt;&lt;p&gt;Our results show a particular spatio-temporal coral distribution with glacial presence only at the deepest sites of the Gulf of Cadiz (~1000m), followed by ~300m Western Mediterranean (WMed) coral appearance across the deglaciation/mid Holocene (14-4 kyr), to end with a proliferation at the Strait of Gibraltar and Galicia Bank from ~6 kyr towards the present. We hypothesise 1) that ~300m WMed area might have been bathed in Atlantic waters inflow during the glacial due to sea-level drop, returning to LIW (Levantine Intermediate Water) influence over the deglaciation, and 2) that MOW reached deeper areas outside of the Mediterranean Sea in the Gulf of Cadiz during the glacial period. Regarding the reservoir age, little change at the WMed is observed at 150-450m across the deglaciation as compared to the large ventilation excursion detected in the Iberian Margin at ~1000m. However, a ventilation age gradient of ~300 yr related to water depth is observed within WMed corals when appearing at the B&amp;#248;lling-Aller&amp;#248;d, in synchrony with significant changes in hydrographical parameters inferred from foraminiferal trace element from the same area. Overall, our results suggest a water mass reorganization at the surface-intermediate layer of the WMed during the deglaciation and early Holocene, but the ultimate nature of these changes needs yet to be explored by further analysis of Nd isotopes as well as of trace elements beyond the deglaciation.&lt;/p&gt;

scholarly journals Spatio-temporal variability and controls on methane and nitrous oxide in the Guadalquivir Estuary, Southwestern Europe

2018 ◽  
Vol 80 (3) ◽  
Author(s):  
I. Emma Huertas ◽  
Susana Flecha ◽  
Gabriel Navarro ◽  
Fiz F. Perez ◽  
Mercedes de la Paz
Keyword(s):  
Nitrous Oxide ◽  
Temporal Variability ◽  
Guadalquivir Estuary ◽  
Spatio Temporal

The influence of phytoplankton biomass on the spatial distribution of carbon dioxide in surface sea water of a coastal area of the Gulf of Cádiz (southwestern Spain)

2005 ◽  
Vol 83 (7) ◽  
pp. 929-940 ◽  
Author(s):  
Emma Huertas ◽  
Gabriel Navarro ◽  
Susana Rodríguez-Gálvez ◽  
Laura Prieto
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Anhydrase ◽  
Primary Production ◽  
Coastal Area ◽  
Phytoplankton Biomass ◽  
Carbon Fixation ◽  
Sea Water ◽  
Gulf Of Cadiz ◽  
Transparent Exopolymer Particles ◽  
Gulf Of Cádiz

The spatial variability in carbon dioxide in surface waters of a coastal area of the Gulf of Cádiz (southwestern Spain) was examined in situ under spring bloom conditions. The influence of phytoplankton biomass and physicochemical variables on the CO2 concentration was studied. According to the relationship observed between chlorophyll a and pCO2, phytoplankton biomass was the main factor responsible for variations in carbon dioxide. The distribution of organic matter in the form of dissolved organic carbon and transparent exopolymer particles also reflected changes in phytoplankton abundance, since high levels of both variables were associated with high chlorophyll concentrations and low levels of free CO2. The involvement of the enzyme carbonic anhydrase in the process of inorganic carbon uptake by the phytoplankton community was also investigated through the effect of the inhibitors dextran-bound sulfonamide and ethoxyzolamide on primary production rates. Ethoxyzolamide substantially inhibited carbon fixation, causing decreases of 40%–60% in the maximum photosynthetic rates; whereas the membrane impermeable inhibitor dextran-bound sulfonamide affected primary production, depending on the diversity of the phytoplankton species composition. Calculations of CO2 fluxes indicated that the sampled coastal sector of the Gulf of Cádiz behaved as a net sink for atmospheric CO2 at the time of analysis, with an average CO2 absorption of –0.41 mmol·m–2·d–1.Key words: air–sea exchange of CO2, carbonic anhydrase, flow cytometry, Gulf of Cádiz, phytoplankton, transparent exopolymer particles.

The Gulf of Cádiz pelagic ecosystem: A review

2007 ◽  
Vol 74 (2-3) ◽  
pp. 228-251 ◽  
Author(s):  
Jesús García Lafuente ◽  
Javier Ruiz
Keyword(s):  
Gulf Of Cadiz ◽  
Pelagic Ecosystem ◽  
Gulf Of Cádiz

scholarly journals The role of neo-tectonics in the sedimentary infilling and geomorphological evolution of the Guadalquivir estuary (Gulf of Cadiz, SW Spain) during the Holocene

Geomorphology ◽  
2014 ◽  
Vol 219 ◽  
pp. 126-140 ◽  
Author(s):  
Antonio Rodríguez-Ramírez ◽  
Enrique Flores-Hurtado ◽  
Carmen Contreras ◽  
Juan J.R. Villarías-Robles ◽  
Gonzalo Jiménez-Moreno ◽  
...  
Keyword(s):  
Gulf Of Cadiz ◽  
Guadalquivir Estuary ◽  
The Holocene ◽  
Sw Spain ◽  
Gulf Of Cádiz ◽  
Geomorphological Evolution
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