Dynamics and size structure of phytoplankton in the coastal waters of Singapore

In this paper, a study on phytoplankton dynamics and size in the tropical coastal waters of Singapore is presented. Chlorophyll-a levels in the Singapore Strait generally range from 0.4 to 10 µg l -1 , with an average value of 1.7 µg l -1 . In general, higher chlorophyll concentrations are typically found off the east coast of Singapore, as well as in the shallower, more protected waters of the Johor Strait (maximum ~78 µg l -1 , average = 21.5 µg l -1 ). Seasonal trends in chlorophyll and nutrients are also apparent, with higher chlorophyll generally observed during the south-west monsoon compared with the wetter north-east monsoon. Size-fractionated chlorophyll measure- ments of the phytoplankton community show that for low standing stocks of chlorophyll less than 3µ g l -1 , approximately 40% of the phytoplankton lies in the pico- and small nanoplankton (<8 µm) size range. As total chlorophyll levels in the system increase, the relative contribution from the larger size classes (i.e. 8-20 and 20-100 µm) increases, with a subsequent decrease in the smaller size classes. For total chlorophyll greater than 40 µg l -1 , it was found that the 20-100 µm size class contributed 60% of total chlorophyll. In contrast, the <8 µm size class contributed only about 5% of total chloro- phyll for these waters.

[1]  Ah Kow Tham.  A preliminary study of the physical, chemical and biological characteristics of Singapore Straits , 1953 .

[2]  R. Hopcroft,et al.  Phytoplankton size fractions in a tropical neritic ecosystem near Kingston, Jamaica , 1990 .

[3]  D. Caron,et al.  The contribution of microorganisms to particulate carbon and nitrogen in surface waters of the Sargasso Sea near Bermuda , 1995 .

[4]  Manfred Ehrhardt,et al.  Methods of seawater analysis , 1999 .

[5]  K. Denman,et al.  The structure of pelagic marine ecosystems. , 1978 .

[6]  P. Falkowski.  Primary productivity in the sea , 1980 .

[7]  D. Menzies,et al.  Particle size distributions in a region of coastal upwelling analyzed by characteristic vectors1 , 1975 .

[8]  R. Olson,et al.  Seasonal and depth variation in microbial size spectra at the Bermuda Atlantic time series station , 1999 .

[9]  J. R. Lara-Lara,et al.  Phytoplankton biomass and primary productivity by size classes in the Gulf of Tehuantepec, México , 1993 .

[10]  T. Berman.  Size fractionation of natural aquatic populations associated with autotrophic and heterotrophic carbon uptake , 1975 .

[11]  L. M. Dickie,et al.  Body-size spectra of production and biomass as system-level indicators of ecological dynamics , 1991 .

[12]  L. Shapiro,et al.  Diurnal variations in photosynthetic rates: comparisons of ultraphytoplankton with a larger phytoplankton size fraction , 1985 .

[13]  O. Holm‐Hansen,et al.  Microbial autotrophic and heterotrophic eucaryotes in Antarctic waters : relationships between biomass and chlorophyll, adenosine triphosphate and particulate organic carbon , 1990 .

[14]  R. Olson,et al.  Pigments, size, and distributions of Synechococcus in the North Atlantic and Pacific Oceans , 1990 .

[15]  R. A. Estudillo,et al.  Red tides and paralytic shellfish poisoning in the Philippines , 1984 .

[16]  E. Arnold,et al.  Standard methods for the examination of water and wastewater. 16th ed. , 1985 .

[17]  A. E. Greenberg,et al.  Standard methods for the examination of water and wastewater : supplement to the sixteenth edition , 1988 .

[18]  T. Malone.  Size-Fractionated Primary Productivity of Marine Phytoplankton , 1980 .

[19]  Patrick Raimbault,et al.  Size fraction of phytoplankton in the Ligurian Sea and the Algerian Basin (Mediterranean Sea): size distribution versus total concentration , 1988 .

[20]  S. Chuang.  Animal life and nature in Singapore , 1973 .

[21]  F. Jochem,et al.  Productivity regime and phytoplankton size structure in the tropical and subtropical North Atlantic in spring 1989 , 1993 .

[22]  R. Peters.  The Ecological Implications of Body Size , 1983 .

[23]  T. Thingstad,et al.  Control of phytoplankton growth in nutrient recycling ecosystems. Theory and terminology , 1990 .

[24]  J. Ryther.  Photosynthesis and fish production in the sea. , 1969, Science.

[25]  F. Jochem,et al.  Productivity regime and phytoplankton size structure in the Arabian Sea , 1993 .

[26]  U. Bathmann,et al.  Distribution patterns of autotrophic pico- and nanoplankton and their relative contribution to algal biomass during spring in the Atlantic sector of the Southern Ocean , 1997 .

[27]  A. Iriarte.  Size-fractionated chlorophyll a biomass and picophytoplankton cell density along a longitudinal axis of a temperate estuary (Southampton Water) , 1993 .