|Onderzoek naar de betrouwbaarheid van de 14C-methode met behulp van track-autoradiografie|
Wildschut, M.A. (1981). Onderzoek naar de betrouwbaarheid van de 14C-methode met behulp van track-autoradiografie. Interne verslagen Nederlands Instituut voor Onderzoek der Zee, 1981(6). NIOZ: Texel. 32 pp.
Deel van: Interne verslagen Nederlands Instituut voor Onderzoek der Zee. Nederlands Insituut voor Onderzoek der Zee, meer
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There are many difficulties when measuring primary production of aquatic ecosystems by the 14c-method. The most pronounced problem is that one measures on the system-level whereas the results consist of the combined effect of (1) the physiological properties of the different algal species and (2) the interactions between autotrophs and heterotrophs. Excretion turned out to be negligible. In order to have a control on the existence of "bottle-enclosure effects", a series of short incubations was carried out simultaneously with a long incubation. Over the same time the production of the short incubations was less than that of the one long incubation. This may be caused by a temporal decrease of the rate of production at the beginning of the incubation. A third factor, the influence of the bacterioplankton on 14C results, could not be investigated because of methodological problems. For measuring the primary production on the species level autoradiography seemed a suitable method. When using a light microscope two variants are possible: grain density and track- autoradiography. For quantative application track-autoradiography should be the method of choice because there is no relevant background, which makes interpretation of the auto- radiograms more reliable. In practice this method proved to be a difficult one. The problems encountered are discussed in detail. Primary production estimates from track-counts agreed well with those calculated from carbon content of the cell and doubling-time.