Scientia Marina, Vol 80, No S1 (2016)

Variability of mesozooplankton biomass and individual size in a coast-offshore transect in the Catalan Sea: relationships with chlorophyll a and hydrographic features

Miquel Alcaraz
Institut de Ciències del Mar, CSIC , Spain

Albert Calbet
Institut de Ciències del Mar, CSIC , Spain

Stamatina Isari
Institut de Ciències del Mar, CSIC - King Abdullah University of Science and Technology , Spain

Xabier Irigoien
King Abdullah University of Science and Technology , Saudi Arabia

Isabel Trepat
Institut de Ciències del Mar, CSIC , Spain

Enric Saiz
Institut de Ciències del Mar, CSIC , Spain


The temporal and spatial changes of zooplankton and chlorophyll a concentration were studied during the warm stratification period (early June) at three stations whose traits corresponded to the coastal, frontal, and offshore-dome water conditions described for the Catalan Sea. We sampled the stations for 12 days at a frequency ranging from less than 10 to 102 h, with a spatial resolution ranging from 10 to 104 m. The objective was to determine the variability of mesozooplankton and phytoplankton (chlorophyll a) biomass, and average individual size (mass) across a coast-offshore transect in relation to the stratification conditions prevailing in the NW Mediterranean during summer. The vertical distribution of phytoplankton biomass displayed a clear deep maximum at 60 m depth except at the coastal station. This maximum exists during most of the year and is especially important during the density stratification period. It was accompanied during daylight hours by a coherent zooplankton maximum. At sunset mesozooplankton ascended and dispersed, with larger organisms from deeper layers joining the migrating community and increasing the average individual mass. The highest variability of mesozooplankton biomass, individual mass and chlorophyll a concentration occurred at the front station due to the coupling between the vertical migration of zooplankton and the particular characteristics of the front. According to the data shown, the highest variability was observed at the lowest scales.


zooplankton biomass; NW Mediterranean; spatial distribution; short-term variability

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Abelló P., Oro D. 1998. Offshore distribution and assemblages of breeding seabirds in the Catalano-Balearic Sea (northwestern Mediterranean). Colonial Waterbirds 21: 422-426.

Acinas S.G., Rodríguez-Valera F., Pedrós-Alió C. 1997. Spatial and temporal variation in marine bacterioplankton diversity as shown by RFLP fingerprinting of PCR amplified 16S rDNA. FEMS Microbiol. Ecol. 24: 27-40.

Agawin N.S.R., Agustí S. 1997. Abundance, frequency of dividing cells and growth rates of Synechococcus sp. (cyanobacteria) in the stratified Northwestern Mediterranean Sea. J. Plankton Res. 19: 1599-1615.

Alcaraz M. 1977. Muestreo cuantitativo de zooplancton: análisis comparativo de la eficacia de mangas y botellas en un sistema estuárico. Inv. Pesq., 41: 258-294.

Alcaraz M. 1980. Evolución y distribución vertical de la biomasa de zooplancton expresada en carbono y nitrógeno orgánicos, relación C/N y carbono detrítico, en una zona marina afectada por aguas residuales de la ciudad de Barcelona. Inv. Pesq., 44: 265-274.

Alcaraz M. 1985. Vertical distribution of zooplankton biomass during summer stratification in the Western Mediterranean. In: Gibbs P.E. (ed.), Proceedings of the 19th EMBS. Cambridge Univ. Press, Cambridge, pp. 135-143.

Alcaraz M. 1988. Summer zooplankton metabolism and its relation to primary production in the Western Mediterranean. In: Minas H.J., Nival P. (eds), Océanograaphie pélagique méditeerranéenne. Oceanol. Acta Nº SP 9, pp. 185-191.

Alcaraz M., Estrada M., Flos J., et al. 1985. Particulate carbon and nitrogen and plankton biomass in oligotrophic and upwelling systems. In: Bas C., Margalef R., Rubies P. (eds), Simposio Internacional sobre las áreas de afloramiento más importantes del Oeste Africano, CSIC, Barcelona: 435-448.

Alcaraz M., Saiz E., Estrada M. 1994. Excretion of ammonia by zooplankton and its potential contribution to nitrogen requirements for primary production in the Catalan Sea (NW Mediterranean). Mar. Biol. 119: 69-76.

Alcaraz M., Saiz E., Calbet A., et al. 2003. Estimating zooplankton biomass through image analysis. Mar. Biol. 143: 307-315.

Alcaraz M., Calbet A., Estrada M., et al. 2007. Physical control of zooplankton communities in the Catalan Sea. Prog. Oceanogr. 74: 294-312.

Alcaraz M., Almeda R., Calbet A., et al. 2010. The role of arctic zooplankton in biogeochemical cycles: respiration and excretion of ammonia and phosphate during summer. Polar Biol. 33: 1719-1731.

Boucher J. 1984. Localization of zooplankton populations in the Ligurian marine front: role of ontogenic migration. Deep Sea Res. 31: 469-484.

Boucher J., Ibanez F., Prieur L. 1987. Daily and seasonal variations in the spatial distribution of zooplankton populations in relation to the physical structure in the Ligurian sea front. J. Mar Res. 45: 133-173.

Calbet A., Alcaraz M., Saiz E., et al. 1996. Planktonic herbivorous food webs in the Catalan Sea (NW Mediterranean): temporal variability and comparison of indices of phyto-zooplankton coupling based in state variables and rate processes. J Plankton Res. 18: 2329-2347.

Calbet A., Garrido S., Saiz E., et al. 2001. Annual zooplankton succession in coastal NW Mediterranean waters: the importance of the smaller size fractions. J. Plankton Res. 23: 319-331.

Calbet A., Saiz E., Alcaraz M. 2002. Copepod eggproduction in the NW Mediterranean: effects of winter environmental conditions. Mar. Ecol. Prog. Ser. 273: 173.184.

Donaghay P.L., Rines H.M., Sieburt J.McN. et al. 1992. Simultaneous sampling of fine scale biological, chemical and physical structure in stratifed waters. Arch. Hydrobiol. Beih. 36: 97-108.

Enright J.T. 1977. Copepods in a hurry: sustained high-speed upward migration. Limnol. Oceanogr. 22: 118-125.

Estrada M. 1985. Deep phytoplankton and chlorophyll maxima in the Western Mediterranean. In: Moraitou-Apostoulou M., Kiortsis V. (eds), Mediterranean marine ecosystems. Plenum Press, New York, pp. 247-277.

Estrada, M. 1996. Primary production in the northwestern Mediterranean. Sci. Mar. 60: 55-64.

Estrada M., Margalef R. 1988. Supply of nutrients to the Mediterranean photic zone along a persistent front. In: Minas H.J., Nival P. (eds), Océanographie pélagique méditerranéenne, Oceanol. Acta Nº SP 9: 133-142.

Fasham M.J.R. 1978. The statistical and mathematical analysis of plankton patchiness. Oceanogr. Mar. Biol. Ann. Rev. 16: 43-79.

Fasham M.J.R., Angel M.V., Roe S.J. 1974. An investigation of the spatial pattern of zooplankton using the Longhurst-Hardy plankton recorder. J. Exp. Mar. Biol. Ecol. 16: 93-112.

Fernández de Puelles M.L., Valencia J., Jansá J., et al. 2004. Hydrographical characteristics and zooplankton distribution in the Mallorca channel (Western Mediterranean): spring 2001. ICES J. Mar. Sci. 61: 654-666.

Font J., Salat J., TintoréJ. 1988. Permanent features of the circulation in the Catalan sea. In: Minas H.J., Nival P. (eds), Pelagic Mediterranean oceanography. Oceanol. Acta, 9: 51-57.

Haury L.R. 1973. Sampling biass of a Longhurst-Hardy Plankton Recorder. Limnol. Oceanogr. 18: 500-506.

Haury L.R. 1976a. Small-scale pattern of a California current zooplankton assemblage. Mar. Biol. 37: 137-155.

Haury L.R. 1976b. A comparison of zooplankton patterns in the California current and North Pacific Central Gyre. Mar. Biol. 37: 159-167.

Haury L.R., Mc Gowan J.A., Wiebe P.H. 1978. Patterns and processes in the time-space scales of plankton distributions. In: Steele J.H. (ed.), Spatial pattern on plankton communities. Plenum Press, NY, pp. 277-327.

Krause M., Radach G. 1989. On the relations of vertical distribution, diurnal migration and nutritional state of herbivorous zooplankton in the northern North Sea during FLEX 1976. Int. Revue ges. Hydrobiol. 74: 371-417.

Longhurst A.R., Reith A.D., Bower R.E., et al. 1966. A new system for the collection of multiple serial plankton samples. Deep Sea Res. 13: 213-222.

Mazzocchi M.G., Siokou I., Tirelli V., et al. 2014. Regional and seasonal characteristics of epipelagic mesozooplankton in the Mediterranean Sea based on an artificial neural network analysis. J. Mar. Syst. 135: 64-80.

Pinot J.M., Jansá J. 2001. Time variability of acoustic backscatter from zooplankton in the Ibiza channel (western Mediterranean). Deep Sea Res. 48: 1651-1670.

Sabatés A., Olivar P. 1996. Variation of larval fish distributions associated with variability in the location of a shelf-slope front. Mar. Ecol. Prog. Ser. 135: 11-20.

Saiz E., Alcaraz M. 1990. Pigment gut contents of copepods and deep phytoplankton maximum in the Western Mediterranean. J Plankton Res. 12: 665-672.

Saiz E., Rodriguez V., Alcaraz M. 1992. Spatial distribution and feeding rates of Centropages typicus in relation to frontal structures in the Catalan Sea (Western Mediterranean). Mar. Biol. 112: 49-56.

Saiz E., Calbet A., Trepat I., et al. 1997. Food availability as a potential source of bias on the egg production method for copepods. J. Plankton Res. 19: 1-14.

Salat J. 1996. Review of hydrographic environmental factors that may influence anchovy habitats in northwestern Mediterraneaan. Sci. Mar. 60: 21-32.

Smith P.E., Ohman M.D., Eber L.E. 1989. Analysis of the patterns of distribution of zooplankton aggregations from an accoustic doppler current profiler. CalCOFI Rep. 30: 88-103.

Stavn R.H. 1971. The horizontal-vertical distribution hypothesis: Langmuir circulations and Daphnia distributions. Limnol. Oceanogr. 16: 453-446.

Steele J.H., Henderson E.W. 1992. A simple model for plankton patchiness. J. Plankton Res. 14: 1397-1403.

Stommel H. 1963. Varieties of oceanographic experience. Science 139: 572-576. PMid:17788284

Turner J.T. 2004. The importance of small planktonic copepods and their roles in pelagic marine food webs. Zool. Stud. 43: 255-266.

Vance T.C., Doel R.E. 2010. Graphical methods and cold war scientific practice: the Stommel diagram's intriguing journey from the physical to the biological sciences. Hist. Stud. Nat. Sci. 40: 1-47. PMid:20514742

Winsor C.P., Clarke G.L. 1940. A statistical study of variation in the catch of plankton nets. J. Mar. Res. 3: 1-34.

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

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