• PDF

    Final published version, 220 KB, PDF-document

    Request copy


Microphytobenthic biomass and primary production were studied at two sampling sites in the northern German Wadden Sea from October 1996 to September 1997. Net oxygen production of the algae in the first millimetre of sediment, which was suspended in filtered seawater, was measured in the laboratory. The 'photosynthetic light dispensation system' in combination with a Clark type electrode was tested for its applicability for sediment slurries. Advantages and limitations of the system compared with other methods of primary production measurement are discussed. Primary production (pB(max)) was between 0.01 and 2.66 mg C mg Chl a(-1) h(-1). Photosynthetic parameters such as the initial slope of the P-E curve (a(B)) and the light saturation parameter (E-k) reached a maximum of 0.034 mug C mug Chl a(-1) h(-1) (muE m(-2) s-(1'))(-1) and 141 muE m(-2) s(-1), respectively. Daily production, calculated on the basis of daily irradiance, normally ranged from 0.27 to 448.9 mg C m(-2) d(-1). Chlorophyll a content varied between 2.21 and 38.34 mg m(-2) Both sampling sites showed large variation in chlorophyll a concentration during the seasons studied, which might be caused by changing environmental conditions and patchy distribution. Variation in photosynthetic parameters might also be due to varying physiological status of the algae and changing environmental conditions. A maximum in spring and autumn biomass was found at 'Hedwigenkoog'. On the contrary, no clear seasonal trend was found in chlorophyll a at 'Busum', but photosynthetic parameters showed an increase during summer. Only at this station were daily production and photosynthetic parameters significantly correlated with physical parameters. [KEYWORDS: P-E parameters; microphytobenthos; daily production; German Wadden Sea Ems-dollard estuary; benthic microalgae; intertidal microphytobenthos; tidal flat; biological-research; diatoms; chlorophyll; sediment; mudflat; phytoplankton]
Original languageEnglish
Pages (from-to)651-662
JournalEstuarine Coastal and Shelf Science
Issue number5
StatePublished - 2000

ID: 305514