Primary and community production in the Southern Bight of the North Sea deduced from oxygen concentration variations in the spring of 1980
Tijssen, S.B.; Eijgenraam, A. (1982). Primary and community production in the Southern Bight of the North Sea deduced from oxygen concentration variations in the spring of 1980. Neth. J. Sea Res. 16: 247-259
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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| Authors | | Top |
- Tijssen, S.B.
- Eijgenraam, A.
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| Abstract |
In March and April 1980 community metabolism was measured through 4 hourly oxygen determinations at 3 depths in a water mass marked with a subsurface drifter. The experiments were carried out in the area of maximum salinity 80 km W of Den Helder. In March oxygen percentages of 101 % were found; an incomplete 48 h curve was constructed and a net oxygen production of 1.4 g. m-2 .d -1 was estimated (0.4 g C.m-2.d-1). In April, during calm weather and high solar irradiance, a mean oxygen percentage of 118% in a Phaeocystis bloom was found. A 72 hours oxygen curve showed a regular diurnal rhythm from which a daily oxygen increase of 3.2% was computed. Maximum hourly production values increased linearly from day to day. Net and gross O2 production values were 11.0 and 14.2 g. m-2. d-2, corresponding with C values of 2.4 and 3.2 g. m-2. d-1. The importance of oxygen exchange with the atmosphere was discussed. A community carbon production for the period 11 March to 17 April of 24 g.m-2 was assumed. Heterotrophs will play a significant role in community metabolism. Horizontal variability appeared to be a disturbing factor in obtaining consistent diurnal curves. Vertical oxygen gradients can play a part in exchange studies in well-mixed regions. |
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