Abstract
The progress curves of 14C retention for samples of phytoplankton from the Irish Sea incubated at contrasting light intensities have been obtained by two methods. The first method (A) involved the incubation of the samples for various periods up to 6 h, while the second method (B) consisted of making a series of short-term incubations over the same 6 h period. Over this period, the cumulative uptake was tenerally less when estimated by Method A than by Method B. The difference was greater in the samples incubated at the lower light intensity, the light history of the samples having no effect on the difference. The differences has a kinetic basis, with two combinations of progress curves obtained by use of the two methods. The first combination was associated with samples collected in the early morning, while the second combination was exhibited by samples taken in the afternoon irrespective of sampling depth. In certain samples, no increase in the 14C retained by the cells as measured by Method A was observed after 4 h. The cumulative retention of 14C by the cells after 2 h was generally greater when estimated by Method A than by Method B, this situation being reversed after 4 h. This reversal indicated a change in uptake kinetics between 2 and 4 h and it is suggested that this interval represents the time necessary for the 14C to work through the cellular pool of carbon. The findings are discussed in relation to the methodology for obtaining both estimates of primary production and 14C uptake-light intensity curves for marine phytoplankton.
Similar content being viewed by others
Literature Cited
Barnett, A.M. and J. Hirota: Changes in the apparent rate of 14C uptake with length of incubation period in natural phytoplankton populations. Limnol. Oceanogr. 11, 349–353 (1966)
Hobson, L.A., W.J. Morris and K.L. Pirquet: Theoretical and experimental analysis of the 14C technique and its use in studies of primary production. J. Fish. Res. Bd Can. 33, 1715–1721 (1976)
Jassby, A.D. and T. Platt: Mathematical formulation of the relationship between photosynthesis and light for phytoplankton. Limnol. Oceanogr. 21, 540–547 (1976)
Quraishi, F.O.: The reaction of phytoplankton to different illumination regimes, Ph.D. thesis, University of Wales 1968
Steeman Nielsen, E. and V.K. Hansen: Influence of surface illumination on plankton photosynthesis in Danish waters (56°N) throughout the year. Physiologia P1. 15, 505–517 (1961)
Strickland, J.D.H. and T.R. Parsons A practical handbook of seawater analysis. Bull. Fish. Res. Bd Can. 167, 1–311 (1968)
Vollenweider, R.A. and A. Nauwerck: Some observations on the C14 method for measuring primary production. Verh. int. Verein. theor. angew. Limnol. 14, 134–139 (1961)
Author information
Authors and Affiliations
Additional information
Communicated by J. Mauchline, Oban
Rights and permissions
About this article
Cite this article
Savidge, G. Variations in the progress of 14C uptake as a source of error in estimates of primary production. Mar. Biol. 49, 295–301 (1978). https://doi.org/10.1007/BF00455024
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00455024