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

• Published in: Scientia Marina
• Main Authors: Anfuso, Eleonora, Ponce, Rocío, Castro, Carmen G., Forja, Jesús M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Consejo Superior de Investigaciones Científicas (España) 2010
• Subjects: Nutrients; Chlorophyll a; Nitracicline; River Guadalquivir; Gulf of Cadiz; Nutrientes; Clorofila-a; Nitraclina; Río Guadalquivir; Golfo de Cádiz; Límite; North Atlantic
• Online Access: http://hdl.handle.net/10261/40496; https://doi.org/10.3989/scimar.2010.74s1047

10 pages, 8 figures, 2 tables [EN] The coupling between the thermohaline, chemical and biological variables on the northeast continental shelf of the Gulf of Cádiz was determined during the Emigas I survey in summer 2006. Samples were collected to chemically characterize the different water types and to analyze the chlorophyll a distribution. Four different water masses were identified: North Atlantic Central Water (NACW), Surface Atlantic Water (SAW), considered a modification of NACW, and South and North Surface Waters. The highest nutrient levels were found in subsurface NACW, while surface waters were almost nutrient-depleted except in the Guadalquivir region. The isopycnal level of 26.3 kg m-3 marked the limit between nutrient-rich NACW and nutrient-poor surface waters. At the offshore stations, the subsurface cholorophyll a maximum was located at the depth of nitracline and associated with the 26.3 kg m-3 isopycnal level rather than with the pycnocline depth. At the inshore stations, chlorophyll a maxima were observed at the bottom, except for the surface maximum in the River Guadalquivir region. [ES] Durante el verano 2006 se llevó a cabo una campaña oceanográfica en la parte NE de la plataforma continental del Golfo de Cádiz para determinar el acoplamiento de las variables termohalinas, químicas y biológicas. En cada estación se tomaron muestras para la caracterización química de las diferentes masas de agua y el análisis de la distribución de clorofila-a. Se diferenciaron cuatro tipos distintos de masas de agua: North Atlantic Central Water (NACW); Surface Atlantic Water (SAW), que es una modificación de la primera y las aguas superficiales del Norte y del Sur. Las concentraciones más elevadas de nutrientes se encontraron asociadas con las aguas profundas (NACW); en cambio las aguas superficiales estaban prácticamente agotadas en nutrientes, con excepción de las estaciones próximas a la desembocadura del Río Guadalquivir. El límite entre NACW rica en nutrientes y las aguas con bajas concentraciones ...