Planktonic primary production in the German Wadden Sea

By combining weekly data of irradiance, attenuation and chlorophyll a concentrations with photosynthesis (P) versus light intensity (E) curve characteristics, the annual cycle of planktonic primary production in the estuarine part of the Northfrisian Wadden Sea was computed for a 2 year period. Daily water column particulate gross production ranged from 5 to 2200 mg C m-2 day-1 and showed a seasonal pattern similar to chlorophyll a. Budget calculation yielded annual gross particu- late primary productions of 124 and 176 g C m-2 year-1 in 1995 and 1996, respectively. Annual amounts of phytoplankton respiration, calculated according to a two-compartment model of Langdon (in Li,W.K.W. and Maestrini,S.Y. (eds), Measurement of Primary Production from the Molecular to the Global Scale. International Council for the Exploration of the Sea, Copenhagen, 1993, pp. 20-36), and dissolved production in 1996, were both in the range of 24-39 g C m-2 year-1. Annual total net produc- tion was thus very similar to particulate gross production (127 and 177 g C m-2 year-1 in 1995 and 1996, respectively). Phytoplankton growth was low or even negative in winter. In spring and summer, production/biomass (Pr/B) ratios varied from 0.2 up to 1.7. Phytoplankton growth during the growth season always surpassed average flushing time in the area, thus underlining the potential of local phytoplankton bloom development in this part of the Wadden Sea. The chlorophyll-specific maximum photosynthetic rate (PB max) ranged from 0.8 to 9.9 mg C mg-1 Chl h-1 and was strongly correlated with water temperature (r2 = 0.67). By contrast, there was no clear seasonal cycle inB, which ranged from 0.007 to 0.039 mg C mg-1 Chl h-1 (µmol photons m-2 s-1)-1. Its variability was much less than PB max and independent of temperature. The magnitude and part of the variability of P B max andB are presumably caused by changes in species composition, as evidenced from the range of these parameters found among 10 predominant diatom species isolated from the Wadden Sea. The ratio of average light conditions in the water column (Eav) to the light saturation parameter Ek indicates that primary production in the Wadden Sea region under study is predominantly controlled by light limi- tation and that nutrient limitation was likely to occur for a few hours per day only during 5 (dissolved inorganic nitrogen) to 10 (PO4, Si) weeks in the 2 year period investigated.

[1]  J. Birrien,et al.  Nutrients and primary production in permanently well-mixed temperate coastal waters , 1983 .

[2]  B. Cole,et al.  An empirical model for estimating phytoplankton productivity in estuaries , 1987 .

[3]  R. Guillard,et al.  Studies of marine planktonic diatoms. I. Cyclotella nana Hustedt, and Detonula confervacea (cleve) Gran. , 1962, Canadian journal of microbiology.

[4]  U. Tillmann,et al.  Factors controlling phytoplankton distribution in coastal waters of the German Bight (North Sea) , 1995 .

[5]  P. Falkowski,et al.  Parameters of photosynthesis: Definitions, theory and interpretation of results , 1997 .

[6]  M. Sullivan,et al.  WATER COLUMN PRODUCTIVITY ATTRIBUTABLE TO DISPLACED BENTHIC DIATOMS IN WELL‐MIXED SHALLOW ESTUARIES 1 , 1988 .

[7]  Geir Johnsen,et al.  Pigment composition, spectral characterization and photosynthetic parameters in Chryso-chromulma polylepis , 1992 .

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

[9]  A. Keller.  An empirical model of primary productivity (14C) using mesocosm data along a nutrient gradient , 1988 .

[10]  J. Cloern.  PHYTOPLANKTON BLOOM DYNAMICS IN COASTAL ECOSYSTEMS' A REVIEW WITH SOME GENERAL LESSONS FROM SUSTAINED INVESTIGATION OF SAN FRANCISCO , 1996 .

[11]  J. Cloern,et al.  Phytoplankton growth rates in a light-limited environment, San Francisco Bay , 1988 .

[12]  B. Prézelin,et al.  Diel oscillations of the photosynthesis-irradiance (P-I) relationship in natural assemblages of phytoplankton , 1982 .

[13]  R. Asmus.  Field measurements on seasonal variation of the activity of primary producers on a sandy tidal flat in the northern Wadden sea , 1982 .

[14]  I. Davison.  ENVIRONMENTAL EFFECTS ON ALGAL PHOTOSYNTHESIS: TEMPERATURE , 1991 .

[15]  Hugh L. MacIntyre,et al.  Primary production by suspended and benthic microalgae in a turbid estuary: time-scales of variability in San Antonio Bay, Texas , 1996 .

[16]  P. Holligan,et al.  Photosynthetic parameters of phytoplankton from 50°N to 50°S in the Atlantic Ocean , 1999 .

[17]  J. Kromkamp,et al.  Primary production of phytoplankton in a turbid coastal plain estuary, the Westerschelde (The Netherlands) , 1993 .

[18]  J. Pennock.  Phytoplankton production in the Delaware Estuary: temporal and spatial variation. , 1986 .

[19]  T. Parsons,et al.  Simulation study of phytoplankton photosynthesis and growth in the Fraser River estuary , 1973 .

[20]  P. Burkholder,et al.  Studies of primary productivity in coastal waters of southern Long Island, New York , 1970 .

[21]  W. Boynton,et al.  A COMPARATIVE ANALYSIS OF NUTRIENTS AND OTHER FACTORS INFLUENCING ESTUARINE PHYTOPLANKTON PRODUCTION , 1982 .

[22]  Thomas M. Powell,et al.  Spatial and temporal variability in South San Francisco Bay (USA). II. Temporal changes in salinity, suspended sediments, and phytoplankton biomass and productivity over tidal time scales , 1989 .

[23]  B. L. Peierls,et al.  Can phytoplankton maintaina positive carbon balance in a turbid, freshwater, tidal estuary? , 1992 .

[24]  Graham P. Harris,et al.  Photosynthesis, productivity and growth, the physiological ecology of phytoplankton , 1978 .

[25]  J. Strickland.  A practical hand-book of seawater analysis , 1972 .

[26]  J. Kromkamp,et al.  Possibility of Net Phytoplankton Primary Production in the Turbid Schelde Estuary (Sw Netherlands) , 1995 .

[27]  I. Joint,et al.  Phytoplankton biomass and production in the southern North Sea , 1993 .

[28]  L. Boorman.  Flora and vegetation of the wadden sea: Edited by W.J. Wolff. A.A. Balkema, Rotterdam, 1979. Pp. 206, 47 text-figures including 3 black-and-white photographs. 17 × 24 cm. ISBN 90 6191 053 6. Price £3·95 , 1981 .

[29]  B. Cole,et al.  Significance of biomass and light availability to phytoplankton productivity in San Francisco Bay , 1984 .

[30]  C. Yentsch,et al.  The Estimation of Phytoplankton Production in the Ocean from Chlorophyll and Light Data1 , 1957 .

[31]  Hans W. Paerl,et al.  Effects of variable irradiance on phytoplankton productivity in shallow estuaries , 1992 .

[32]  T. Platt,et al.  Phytoplankton production and water motion in surface mixed layers , 1982 .

[33]  G. Cadée,et al.  Primary production of phytoplankton in the Dutch Wadden Sea , 1974 .

[34]  A. Belgrano,et al.  Primary production, climatic oscillations, and physico-chemical processes: the Gullmar Fjord time-series data set (1985–1996) , 1998 .

[35]  L. Ward,et al.  Phytoplankton, nutrients, and turbidity in the Chesapeake, Delaware, and Hudson estuaries , 1988 .

[36]  Paul G. Falkowski,et al.  Primary Productivity and Biogeochemical Cycles in the Sea , 1992 .

[37]  C. Gallegos,et al.  Vertical advection of phytoplankton and productivity estimates: a dimensional analysis , 1985 .

[38]  K. Richardson,et al.  Algal 14C and total carbon metabolisms 2. Experimental observations with the diatom Skeletonema costatum , 1996 .

[39]  L. Edler,et al.  Recommendations on methods for marine biological studies in the Baltic Sea. Phytoplankton and chlorophyll , 1979 .

[40]  Trevor Platt,et al.  Photoinhibition of photosynthesis in natural assemblages of marine phytoplankton , 1980 .

[41]  B. L. Peierls,et al.  Phytoplankton primary production in the tidal, freshwater Hudson River, New York (USA) , 1991 .

[42]  Alan D. Ansell,et al.  Biology and ecology of Shallow coastal waters , 1997 .

[43]  J. Grobbelaar.  Phytoplankton productivity in turbid waters , 1985 .

[44]  P. Carlson,et al.  Carbon and nitrogen primary productivity in three North Carolina estuaries. , 1982 .

[45]  J. Heilmann,et al.  Annual distribution and activity of phytoplankton in the Skagerrak/ Kattegat frontal region , 1994 .

[46]  B. L. Welsh,et al.  The effect of tidal resuspension on the distribution of intertidal epipelic algae in an estuary , 1980 .

[47]  H. Lindeboom.  The ecosystem of the western Wadden Sea: field research and mathematical modelling , 1988 .

[48]  I. Joint,et al.  Primary production in a turbid estuary , 1981 .

[49]  G. Cadée.  Reappraisal of the production and import of organic carbon in the western Wadden Sea , 1980 .

[50]  U. Tillmann,et al.  On the quantitative importance of heterotrophic microplankton in the northern German Wadden Sea , 1998 .

[51]  W. Wolff.  Ecology of the Wadden Sea , 1983 .

[52]  Timothy R. Parsons,et al.  Biological oceanography: an introduction. Second edition , 1997 .

[53]  H. Postma.  Hydrography of the Dutch Wadden Sea , 1954 .

[54]  J. Kromkamp,et al.  Turbidity, nutrients and phytoplankton primary production in the Oosterschelde (The Netherlands) before, during and after a large-scale coastal engineering project (1980-1990) , 1994 .

[55]  James E. Cloern,et al.  Turbidity as a control on phytoplankton biomass and productivity in estuaries , 1987 .

[56]  H. Ridderinkhof,et al.  Tidal exchange between the North Sea and Dutch Wadden Sea and mixing time scales of the tidal basins , 1990 .

[57]  F. Colijn.  The temporal variability of plankton and their physico-chemical environment , 1998 .

[58]  T. Parsons,et al.  A practical handbook of seawater analysis , 1968 .