The biogeochemistry of nutrients, dissolved oxygen and chlorophyll a in the Catalan Sea (NW Mediterranean Sea)


  • Mariona Segura-Noguera Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC - ChELSI Institute, Department of Chemical and Biological Engineering, The University of Sheffield
  • Antoni Cruzado Department of Aquatic Biogeochemistry, Centre d’Estudis Avançats de Blanes, CSIC -
  • Dolors Blasco Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC



dissolved inorganic nutrients, dissolved oxygen, chlorophyll a, stoichiometry, P limitation, NW Mediterranean Sea, Catalan Sea


Reference depth profiles of dissolved inorganic nutrients, dissolved oxygen and chlorophyll a are described for the Catalan Sea using quality controlled data. Phosphate, nitrate and silicate show typical nutrient profiles, with nutriclines at different depths. Maximums of nitrite, dissolved oxygen and occasionally ammonium are found within the photic zone, close to the deep chlorophyll maximum. In intermediate waters we found a minimum of dissolved oxygen coincident with maximum concentrations of phosphate and nitrate. Ammonium concentration is unexpectedly high in the mesopelagic zone, where there are still measurable nitrite concentrations. The origin of such high ammonium and nitrite concentrations remains unclear. We also identify and describe anomalous data and profiles resulting from eutrophication, western Mediterranean Deep Water formation and dense shelf water cascading. The N:P ratio in deep waters is 22.4, which indicates P limitation relative to the Redfield ratio. However, the N:P ratio above the deep chlorophyll maximum in stratified surface waters is < 4 (< 8 including ammonium). The depth profiles of key biogeochemical variables described in this study will be a useful reference for future studies in the Catalan Sea (NW Mediterranean Sea) in order to validate data sampled in this area, to identify anomalous processes, and to study the evolution of the ecosystem following the undergoing global change.


Download data is not yet available.


Arin L., Guillén J., Segura-Noguera M., et al. 2013. Open sea hydrographic forcing of nutrient and phytoplankton dynamics in a Mediterranean coastal ecosystem. Est. Coast. Shelf Sci. 133: 116-128.

Astraldi M., Gasparini G.P. 1992. The seasonal characteristics of the circulation in the North Mediterranean basin and their relationship with the atmospheric-climatic conditions. J. Geophys. Res. 97: 9531-9540.

Bahamón N., Cruzado A. 2003. Modelling nitrogen fluxes in oligotrophic environments: NW Mediterranean and NE Atlantic. Ecol. Model. 163: 223-244.

Ballester A., Arias E., Cruzado A., et al. 1967. Estudio hidrográfico de la costa catalana, de junio de 1965 a mayo de 1967. Inv. Pesq. 31: 621-662.

Benitez-Nelson C.R., Buesseler K.O. 1999. Variability of inorganic and organic phosphorus turnover rates in the coastal ocean. Nature 398: 502-505.

Bertilsson S., Berglund O., Karl D.M., et al. 2003. Elemental composition of marine Prochlorococcus and Synechococcus: Implications for the ecological stoichiometry of the sea. Limnol. Oceanogr. 48: 1721-1731.

Béthoux J.P., Copin-Montégut G. 1986. Biological fixation of atmospheric dinitrogen in the Mediterranean Sea. Limnol. Oceanogr. 31: 1353-1358.

Béthoux J.P., Morin P., Chaumery C., et al. 1998. Nutrients in the Mediterranean Sea, mass balance and statistical analysis of concentrations with respect to environmental change. Mar. Chem. 63: 155-169.

Béthoux J.P., Morin P., Ruiz-Pino D. 2002. Temporal trends in nutrient ratios: chemical evidence of Mediterranean ecosystem changes driven by human activity. Deep-Sea Res. II 49(11): 2007-2016.

Blasco D. 1971. Acumulación de nitritos en determinados niveles marinos por acción del fitopláncton. Ph.D. Thesis, Univ. Barcelona.

Bower C., Holm-Hansen T. 1980. A salycilate-hypochlorite method for determining ammonia in seawater. Can. J. Aquat. Sci. 37: 794-798.

Brzezinski M.A. 1988. Vertical distribution of ammonium in stratified oligotrophic waters. Limnol. Oceanogr. 33(5): 1176-1182.

Canals M., Serra J., Riba O. 1982. Toponímia de la Mar Catalano-Balear (amb un glossari de termes genèrics). Bull. Soc. Hist. Nat. Balears 26: 169-194.

Canals M., Puig P., Durrieu de Madron X., et al. 2006. Flushing submarine canyons. Nature 444: 354-357. PMid:17108962

Canals M., Danovaro R., Heussner S., et al. 2009. Cascades in Mediterranean submarine grand canyons. Oceanography 22(1): 26-43.

Copin-Montégut C., Copin-Montégut G. 1983. Stoichiometry of carbon, nitrogen, and phosphorus in marine particulate matter. Deep-Sea Res. 30: 31-46.

Cruzado A. 1985. Chemistry of Mediterranean Waters. In: Margalef R. (ed.), Western Mediterranean. Pergamon Press, Oxford, pp. 126-147.

Cruzado A., Velásquez Z. 1990. Nutrients and phytoplankton in the Gulf of Lions, northwestern Mediterranean. Cont. Shelf Res. 10(9-11): 931-942.

Cruzado A., Velásquez Z., Perez M.D., et al. 2002. Nutrient fluxes from the Ebre river and subsequent across-shelf dispersion. Cont. Shelf Res. 22: 349-360.

Dafner E.V., Boscolo R., Bryden H.L. 2003. The N:Si:P molar ratio in the Strait of Gibraltar. Geophysical Research Letters 30(10): 1506.

Duarte C.M., Agustí S., Kennedy H., et al. 1999. The Mediterranean climate as a template for Mediterranean marine ecosystems: the example of the northeast Spanish littoral. Prog. Oceanogr. 44: 245-270.

Estrada M. 1985a. Deep phytoplankton and chlorophyll maxima in the Western Mediterranean. In: Moraitou-Apostolopoulou M., Kiorstis V. (Eds), Mediterranean Marine Ecosystems. Plenum Press, New York, pp. 247-277.

Estrada M. 1985b. Primary production at the deep chlorophyll maximum in the Western Mediterranean. In: Gibbs P.E. (ed.), Proc. 19th European Marine Biology Symp., Cambridge University Press, pp. 109-121.

Estrada M. 1996. Primary production in the Northwestern Mediterranean. Sci. Mar. 60(Suppl. 2): 55-64.

Estrada M. 1999. Hidrodinàmica i fitoplàncton en el Mar Català. Memorias de la Real Academia de Ciencias y Artes de Barcelona 961, vol. LVIII(6): 189-247.

Estrada M., Margalef R. 1988. Supply of nutrients to the Mediterranean photic zone along a persistent front. Oceanol. Acta 9(Spec. Issue): 133-142.

Estrada M., Marrasé C., Latasa M., et al. 1993. Variability of deep chlorophyll maximum characteristics in the northwestern Mediterranean. Mar. Ecol. Prog. Ser. 92: 289-300.

Estrada M., Varela R.A., Salat J., et al. 1999. Spatio-temporal variability of the winter phytoplankton distribution across the Catalan and north Balearic fronts (NW Mediterranean). J. Plankton Res. 21: 1-20.

Falster D.S, Warton D.I, Wright I.J. 2006. SMATR: Standarised major axis tests and routines. Available: Fichaut M., Balopoulos E., Baudet L., et al. 1997. A common protocol to assemble a coherent database from distributed heterogeneous data sets: the MEDATLAS database experience. MAST Workshop on Project Data Management, 11-13 June, Ispra, Italy.

Flo E., Camp J. 2005. Programa de Vigilància i Control de la Qualitat Ambiental de les Aigües Litorals a Catalunya 8, Anual any 2.

Font J., Salat J., Tintoré J. 1988. Permanent features of the circulation in the Catalan Sea. Oceanol Acta 9(Spec. Issue): 51-57.

Font J., García-Ladona E., Gorriz E.G. 1995. The seasonality of mesoscale motion in the Northern Current of the western Mediterranean: several years of evidence. Oceanol. Acta 18(2): 207-219.

Geider R., La Roche J. 2002. Redfield revisited: variability of C : N : P in marine macroalgae and its biochemical basis. Eur. J. Phycol. 37: 1-17.

Granata T.C., Estrada M., Zika U., et al. 2004. Evidence for enhanced primary production resulting from relative vorticity induced upwelling in the Catalan current. Sci. Mar. 68(Suppl.1): 113-119.

Guadayol Ò., Peters F. 2006. Analysis of wind events in a coastal area: a tool for assessing turbulence variability for studies on plankton. Sci. Mar. 70: 9-20.

Guadayol Ò., Marrasé C., Peters F., et al. 2009. Responses of coastal osmotrophic planktonic communities to simulated events of turbulence and nutrient load throughout a year. J. Plankton Res. 31(6): 583-600.

Hammer Ø., Harper D.A.T., Ryan P.D. 2001. Paleontological Statistics Software Package for Education and Data Analysis. Palaeontol. Electron. 4: 9.

Hansen H.P., Koroleff F. 1999. Determination of nutrients. In: Grasshoff K., Kremling K., Ehrhardt M. (eds), Methods of Seawater Analysis. Wiley-VCH, Weinheim, New York, pp. 191-228.

Holmes R.M., Aminot A., Kérouel R., et al. 1999. A simple and precise method for measuring ammonium in marine and freshwater ecosystems. Can. J. Fish. Aquat. Sci. 56: 1801-1808.

Hudson J.J., Taylor W.D., Schindler D.W. 2000. Phosphate concentration in lakes. Nature 406: 54-56. PMid:10894537

Isla E., Scharek R., Latasa M. 2015. Zooplankton diel vertical migration and contribution to deep active carbon flux in the NW Mediterranean. J. Mar. Sys. 143: 86-97.

Ivancic I., Godrijan J., Pfannkuchen M., et al. 2012. Survival mechanisms of phytoplankton in conditions of stratification-induced deprivation of orthophosphate: Northern Adriatic case study. Limnol. Oceanogr. 57(6): 1721-1731.

Johnson M., Sanders R., Avgoustidi V., et al. 2007. Ammonium accumulation during a silicate-limited diatom bloom indicates the potential for ammonia emission events. Mar. Chem. 106: 63-75.

Karl D.M., Knauer G.A. 1984. Vertical distribution, transport, and exchange of carbon in the Northeast Pacific Ocean: evidence for multiple zones of biological activity. Deep-Sea Res. 31: 221-243.

Karl D.M., Christian J.R., Dore J.E., et al. 1996. Seasonal and interannual variability in primary production and particle flux at Station ALOHA. Deep-Sea Res. II 43(2-3): 539-568.

Kay A.D., Ashton I.W., Gorokhova E., et al. 2005. Toward a stoichiometric framework for evolutionary biology. Oikos 109: 6-17.

Klausmeier C.A., Litchman E., Daufresne T., et al. 2004. Optimal nitrogen-to-phosphorus stoichiometry of phytoplankton. Nature 429: 171-174. PMid:15141209

Kress N., Herut B. 2001. Spatial and seasonal evolution of dissolved oxygen and nutrients in the Southern Levantine Basin (Eastern Mediterranean Sea): chemical characterization of the water masses and inferences on the N:P ratios. Deep-Sea Res. I 48: 2347-2372.

Krom M.D., Kress N., Brenner S., et al. 1991. Phosphorus limitation of primary productivity in the Eastern Mediterranean Sea. Limnol. Oceanogr. 36(6): 424-432.

Krom M.D., Emeis K.-C., Van Cappellen P. 2010. Why is the Eastern Mediterranean phosphorus limited? Prog. Oceanogr. 85: 236-244.

Longhurst A. 1998. Ecological Geography of the Sea. Academic Press, San Diego.

Longhurst A.R., Harrison W.G. 1988. Vertical nitrogen flux from the oceanic photic zone by diel migrant zooplankton and nekton. Deep Sea Res. A. 35 (6): 881-889.

Margalef R. 1963. El ecosistema pelagico de un area costera del Mediterraneo Occidental. Memorias de la Real Academia de Ciencias y Artes de Barcelona 699, vol. XXXV (1): 1-48.

Margalef R. 1985. Western Mediterranean. Pergamon Press, Oxford.

Margalef R. 1998. Elements limitants, explotabilitat i diversitat. Homenatge a Bolós i al fósfor. Acta Bot. Barc. 45 (Homenatge a Oriol de Bolós): 633-643.

Marty J.-C., Chiavérini J., Pizay M.-D., et al. 2002. Seasonal and interannual dynamics of nutrients and phytoplankton pigments in the western Mediterranean Sea at the DYFAMED time-series station (1991–1999). Deep-Sea Res. II 49: 1965-1985.

Masó M., La Violette P.E., Tintoré J. 1990. Coastal flow modification by submarine canyons along the NE Spanish coast. Sci. Mar. 54(4): 343-348.

MEDOC Group. 1970. Observation of formation of deep water in the Mediterranean Sea. Nature 277: 1037-1040.

Millero F.J. 1996. Chemical Oceanography. CRC Press, Boca Raton, Florida. PMid:18680864

Millot C. 1987. Circulation in the western Mediterranean sea. Oceanol. Acta 10: 149.

Minas H.J., Bonin M.C. 1988. Oxygénation physique et biologique de la Méditerranée nord-occidentale en hiver et au printemps. Oceanol. Acta 9(Spec. Issue): 123-132.

Mostajir B., Fagerbakke K.M., Heldal M., et al. 1998. Elemental composition of individual pico- and nano-sized marine detrital particles in the northwestern Mediterranean Sea. Oceanol. Acta 21(4): 589-596.

Moutin T., Raimbault P. 2002. Primary production, carbon export and nutrients availability in western and Eastern Mediterranean Sea in early summer 1996 (MINOS cruise). J. Mar. Sys. 33: 273-288.

Olson R.J. 1981. Differential photoinhibition of marine nitrifying bacteria-A possible mechanism for the formation of the primary nitrite maximum. J. Mar. Res. 39: 227-238.

Owens W.B., Millard Jr. R.C. 1985. A new algorithm for CTD oxygen calibration. J. Phys. Oceanogr. 15: 621-631.<0621:ANAFCO>2.0.CO;2

Palanques A., Martín J., Puig P., et al. 2006. Evidence of sediment gravity flows induced by trawling in the Palamós (Fonera) submarine canyon (northwestern Mediterranean). Deep-Sea Res. I 53: 201-214.

Pascual A., Buongiorno Nardelli B., Larnicol G., et al. 2002. A case of an intense anticyclonic eddy in the Balearic Sea (western Mediterranean). J. Geophys. Res. 107(C11): 3183.

Pujo-Pay M., Conan P., Oriol L., et al. 2011. Integrated survey of elemental stoichiometry (C, N, P) from the western to eastern Mediterranean Sea. Biogeosciences 8: 883-899.

Raimbault P., Coste B. 1990. Very high values of the nitrate/phosphate ratio (>30) in the subsurface layers of the Western Mediterranean Sea. Rapp. CIESMM 32 (1): 44.

Redfield A.C., Ketchum B.H., Richards F.A. 1963. The influence of organisms on the composition of sea-water. In: Hill M.N. (ed.), The Sea, Vol. 2. The Composition of Seawater. Wiley, New York. PMid:14085379

Ribera d'Alcalà M., Civitarese G., Conversano F., et al. 2003. Nutrient ratios and fluxes hint at overlooked processes in the Mediterranean Sea. J. Geophys. Res. 108: 8106.

Riley J.P. 1971. Micronutrient elements. In: Riley J.P., Chester R. (eds), Introduction to Marine Chemistry. Academic Press, London.

Ríos A.G., Fraga F., Pérez F.F., et al. 1998. Chemical composition of phytoplankton and particulate organic matter in the Ría de Vigo (NW Spain). Sci. Mar. 62(3): 257-271.

Rosen B., Lowe R. 1984. Physiological and ultrastructural responses of Cyclotella meneghiniana (Bacillariophyta) to light-intensity and nutrient limitation. J. Phycol. 20: 173-183.

Saino T., Otobe H., Wada E., et al. 1983. Subsurface ammonium maximum in the northern Pacific and the Bering Sea in summer. Deep-Sea Res. 30: 1157-1171.

Salat J. 1983. Formation d'eau profonde près de la côte catalane au sud du 42ºN. Croisière "Caron 82": premiers resultats. Rapp. Comm. Int. Mer Médit. 28(2): 73-77.

Salat J. 1995. The interaction between the Catalan and Balearic currents in the southern Catalan Sea. Oceanol. Acta 18(2): 227-234.

Salat J. 1996. Review of hydrographic environmental factors that may influence anchovy habitats in northwestern Mediterranean. Sci. Mar. 60(Suppl. 2): 21-32.

Salat J., Cruzado A. 1981. Masses d'eau dans la Mediterranée Occidentale: Mer Catalane et eaux adjacentes. Rapp. Comm Int. Mer Médit. 27(6): 201-209.

Salat J., Font J. 1987. Water mass structure near and offshore the Catalan coast during the winters of 1982 and 1983. Ann. Geophys. B- Terr. Planet. Phys. 5: 49-54.

Salat J., Garcia M., Cruzado A., et al. 2002. Seasonal changes of water mass structure and shelf slope exchanges at the Ebre shelf (NW Mediterranean). Cont. Shelf Res. 22: 327-348.

Sarmiento J.L., Gruber N. 2006. Ocean Biogeochemical Dynamics. Princeton Univ. Press. PMCid:PMC1779284

Send U., Font J., Krahmann G., et al. 1999. Recent advances in observing the physical oceanography of the western Mediterranean Sea. Prog. Oceanogr. 44: 37-64.

Segura-Noguera M., Cruzado A., Blasco D. 2011. Nutrient preservation, analysis precision and quality control of an oceanographic database (inorganic nutrients, dissolved oxygen and chlorophyll a) from the NW Mediterranean Sea. Sci. Mar. 75(2): 321-339.

Segura-Noguera M., Blasco D., Fortu-o J.-M. In press. Taxonomic and environmental variability in the elemental composition and stoichiometry of individual dinoflagellate and diatom cells from the NW Mediterranean Sea. PLoS ONE.

Sournia A. 1973. La production primaire planctonique en Méditerranée: Essai de mise à jour. Bull. Ét. Commun. Médit. 5: 1-28.

Thingstad T.F., Zweifel U.L., Rassoulzadegan F. 1998. P limitation of heterotrophic bacteria and phytoplankton in the northwest Mediterranean. Limnol. Oceanogr. 43: 88-94.

Winkler L.W. 1888. Die Bestimmung des in Wasser gelosten Sauerstoffen. Berichte der Deutschen Chemischen Gesellschaft 21: 2842-2855.

Yentsch C.S., Menzel D.W. 1963. A method for the determination of phytoplankton chlorophyll and phaeophytin by fluorescence. Deep-Sea Res. 10: 221-231.



How to Cite

Segura-Noguera M, Cruzado A, Blasco D. The biogeochemistry of nutrients, dissolved oxygen and chlorophyll a in the Catalan Sea (NW Mediterranean Sea). Sci. mar. [Internet]. 2016Sep.30 [cited 2024Apr.19];80(S1):39-56. Available from: