Seasonal evolution of cholorophyll-a and cyanobacteria (Prochlorococcus and Synechococcus) on the northeast continental shelf of the Gulf of Cádiz: relation to thermohaline and nutrients fields

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.

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

Biogeosciences Discussions ◽

10.5194/bgd-9-14537-2012 ◽

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.

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Methane dynamics in the coastal – Continental shelf transition zone of the Gulf of Cadiz

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2020.106653 ◽

2020 ◽

Vol 236 ◽

pp. 106653 ◽

Cited By ~ 1

Author(s):

A. Sierra ◽

D. Jiménez-López ◽

T. Ortega ◽

M.C. Fernández-Puga ◽

A. Delgado-Huertas ◽

...

Keyword(s):

Continental Shelf ◽

Transition Zone ◽

Gulf Of Cadiz ◽

Gulf Of Cádiz ◽

Methane Dynamics

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Validation of CryoSat-2 SIRAL sea level data in the eastern continental shelf of the Gulf of Cadiz (Spain)

Advances in Space Research ◽

10.1016/j.asr.2017.10.042 ◽

2018 ◽

Vol 62 (6) ◽

pp. 1405-1420 ◽

Cited By ~ 6

Author(s):

J. Gómez-Enri ◽

S. Vignudelli ◽

P. Cipollini ◽

J. Coca ◽

C.J. González

Keyword(s):

Continental Shelf ◽

Sea Level ◽

Gulf Of Cadiz ◽

Level Data ◽

Gulf Of Cádiz

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Coupling between the thermohaline, chemical and biological fields during summer 2006 in the northeast continental shelf of the Gulf of Cádiz (SW Iberian Peninsula)

Scientia Marina ◽

10.3989/scimar.2010.74s1047 ◽

2010 ◽

Vol 74 (S1) ◽

pp. 47-56 ◽

Cited By ~ 5

Author(s):

Eleonora Anfuso ◽

Rocio Ponce ◽

Carmen Gonzalez Castro ◽

Jesús M. Forja

Keyword(s):

Continental Shelf ◽

Iberian Peninsula ◽

Gulf Of Cadiz ◽

Gulf Of Cádiz

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Stratigraphic evidence of an upper Pleistocene TST to HST complex on the Gulf of Cádiz continental shelf (south-west Iberian Peninsula)

Geo-Marine Letters ◽

10.1007/s00367-002-0103-0 ◽

2002 ◽

Vol 22 (2) ◽

pp. 95-107 ◽

Cited By ~ 21

Author(s):

Lobo F. ◽

Hernández-Molina F. ◽

Somoza L. ◽

V. Díaz del Río ◽

Dias J.

Keyword(s):

Continental Shelf ◽

Iberian Peninsula ◽

Gulf Of Cadiz ◽

Upper Pleistocene ◽

South West ◽

Gulf Of Cádiz

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Clay minerals as dynamic tracers of suspended matter dispersal in the Gulf of Cadiz (SW Spain)

Clay Minerals ◽

10.1180/0009855064130215 ◽

2006 ◽

Vol 41 (3) ◽

pp. 727-738 ◽

Cited By ~ 5

Author(s):

J. M. Gutiérrez-Mas ◽

F. López-Aguayo ◽

M. Achab

Keyword(s):

Continental Shelf ◽

Clay Minerals ◽

Continental Margin ◽

Suspended Matter ◽

Gulf Of Cadiz ◽

Sediment Distribution ◽

Sw Spain ◽

Gulf Of Cádiz ◽

Tidal Flows ◽

Cadiz Bay

AbstractThe dispersal of suspended matter in the Gulf of Cadiz (SW Spain) is related to its geographical position near the Strait of Gibraltar, and the continental margin, and to Atlantic and Mediterranean water flows and their interaction with the littoral tidal processes. The main direction for transport of suspended matter is towards the southeast, along the continental margin, from the mouths of the rivers Guadiana and Guadalquivir to the Mediterranean. This general transport pattern is perturbed by littoral processes such as those occurring in Cadiz Bay, where a portion of Atlantic suspended matter, driven by flood tide, comes into the inner bay and is deposited in the shallow waters of lagoons and salt marshes. Subsequently, because of the southeast wind and waves, these sediments are remobilized and transported to the west by the ebb tide, to deeper Atlantic waters. This dynamic interaction between Atlantic and littoral waters generates a different type of sediment layout, the origin of which is difficult to establish.In order to understand the dispersal of the suspended matter and its effects on the inner continental shelf, the distribution of the main clay minerals has been determined by means of X-ray and Q-mode and R-mode factor analysis. The suspended matter dispersal paths were established through the distribution of main clay mineral associations and from the ratios amongst these minerals. The results allow us to determine the importance of the tidal flows in the suspended matter transport system of the Gulf of Cadiz. Therefore, a record was kept of which of the outgoing tidal flows from the inner parts of Cadiz Bay reached the continental shelf. The flows intercept the clear Atlantic waters giving rise to a complex sediment distribution and to the mix of clay minerals. The study has also allowed us to establish the sediment source areas and the extent of sediment transport and the paths they follow.

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