Variability in the size - fractioned distribution of phytoplankton across the Catalan front of the north-west Mediterranean

Author(s): Delgado M, M Latsa, M Estrada

Abstract

The size distribution of the autotrophic pico- and nanoplankton community was studied by means of epifluorescence microscopy in two cruises carried out in May 1989 and February 1990, along two transects in the Catalan Sea (north-western Mediterranean). The contribution of each size class to the total autotrophic carbon biomass (PC) was assessed in the central station of each transect. In the first cruise, the water column was well-stratified, and the maximum phytoplankton concentrations were found at 40–60 m depth, coinciding with the deep chlorophyll maximum (DCM). In the second cruise, which took place during a period of weak stratification, the vertical distribution of the smallest organisms was fairly homogeneous within the euphotic zone, while the largest forms, composed mainly of diatoms, presented a subsurface maximum. Synechococcus spp. and nanoplanktonic microalgae of 2–5 μm contributed 20 and 45%, respectively, of the total autotrophic carbon at the central station of May 1989; while the >20 μm size class (composed mainly of diatoms) accounted for 55% of the autotrophic carbon at the central station of February 1990. Nevertheless, the biomass present in eukaryotic cells <20 μm was similar in both cruises (0.789 and 0.706 g C m−2 in May 1989 and February 1990 respectively). There were few consistent trends regarding preferential abundance of any particular size fraction in the shallower or deeper parts of the euphotic zone, though in general, the proportion of Synechococcus tended to be higher in the DCM than in the upper layers.

Similar Articles

Wind-driven coastal upwelling along the western boundary of the Bay of Bengal during the southwest monsoon

Author(s): Shetye SR, Shenoi SSC, Gouveia AD, Michael GS, Sundar D, et al.

The Western Boundary Current of the seasonal subtropical gyre in Bay of Bengal

Author(s): Shetye SR, AD Gouveia, SSC Shenoi, DSundar, GSMichael, et al.

Hydrography and circulation in the western Bay of Bengal during the northeast monsoon

Author(s): Shetye SR, Gouveia AD, Shankar D, Shenoi SSC, Vinayachandran PN, et al.

Observation of the western boundary current of the Bay of Bengal Deep-Sea Res 44:135-145

Author(s): Sanilkumar KV, Kuruvilla TV, Jogendranath D, and Rao RR

Eddy-mediated biological productivity in the Bay of Bengal during fall and spring intermonsoons Deep Sea Research II 54: 1619-1640

Author(s): Prasanna Kumar S, Nuncio M, Ramaiah N, Sardesai S, Narvekar, Jayu, Fernandes, Veronica, & Paul, Jane T

Are eddies nature’s trigger to enhance biological productivity in the Bay of Bengal? Geophys Res Lett 31

Author(s): Prasanna Kumar S, Nuncio M, Narvekar J, Kumar A, Sardesai S, et al.

Seasonal cycle of physicalforcing and biological response in the Bay of BengalIndian J Mar Sci 39: 388-405

Author(s): Prasanna Kumar S, Nuncio M, Narvekar J, Ramaiah N, Sardessai S, et al

Influence of basin-scale and mesoscale physical processes onbiological productivity in the Bay of Bengal during the summer monsoon

Author(s): Muraleedharan KR, Jasmine P, Achuthankutty CT, Revichandran C, Dineshkumar PK, et al

ICES zooplankton methodology manual

Author(s): Harris RP, Wiebe PH, Lenz JH, Skjoldal R & Huntley M

Detection of Bay of Bengaleddies from Topex and in situ observations

Author(s): Gopalan AKS, GopalaKrishna VV, Ali MM, Sharma R

Forcing mechanisms of the Bay of Bengal circulation Current SciIndia 71: 753-763

Author(s): Vinayachandran PN, Shetye SR, Sengupta D, Gadgil S

Development of a subsurface chlorophyll maximum at the entrance to the Gulf of Finland, Baltic Sea

Author(s): Kononen KJ, S Hallfors, M Kokkonen, H Kuosa, J Laanemets, J Pavelson

Analysis of Marine Ecosystems

Author(s): Owen RW

Vertical flux of respiratory carbon by oceanic diel migrant biota Deep-Sea Res 37: 685–694

Author(s): Longhurst AR, Bedo A, Harrison WG, Head EJH, Sameoto DD

Zooplankton vertical migration and the active transport of dissolved organic and inorganic carbon in the Sargasso

Author(s): Steinberg DK, Carlson CA, Bates NR, Goldthwait SA, Madin LP, et al.