AMMONIUM UPTAKE AND REGENERATION FLUXES OF THE MICROPLANKTON COMMUNITIES IN JIAOZHOU BAY

The results from four cruises(Nov.1991—Jul.1992)to examine fluxes of ammonium uptake andregeneration in the surface layer of Jiaozhou Bay are presented.Seasonal variations of the two fluxeswere in the order:summer>spring>autumn>winter.Diel patterns were characterized by higher uptake inthe daytime and higher regeneration at night.Averaged uptake and regeneration fluxes on an annual scalewere 0.073 and 0.053 μmol·L~(-1)·h~(-1)respectively.Regeneration fluxes were always less than uptakefluxes throughout the year.The longest turnover time was 16.34 d(in winter),and the shortest one was0.68 d(in summer).The major uptake flux was contributed by the smallest fraction-picoplankton.Theextents of light-dependence of ammouium uptake by different size fractions were in the order:netplankton>nanoplankton>picoplankton..

Ammonium uptake and regeneration fluxes of the microplankton communities in Jiaozhou Bay

The results from four cruises (Nov. 1991–Jul. 1992) to examine fluxes of ammonium uptake and regeneration in the surface layer of Jiaozhou Bay are presented. Seasonal variations of the two fluxes were in the order, summer>spring>autumn>winter. Diel patterns were characterized by higher uptake in the daytime and higher regeneration at night. Averaged uptake and regeneration fluxes on an annual scale were 0.073 and 0.053 μmol·L⁻¹·h⁻¹ respectively. Regeneration fluxes were always less than uptake fluxes throughout the year. The longest turnover time was 16.34 d (in winter), and the shortest one was 0.68 d (in summer). The major uptake flux was contributed by the smallest fraction-picoplankton. The extents of light-dependence of ammouium uptake by different size fractions were in the order: netplankton>nanoplankton>picoplankton. Contribution No. 2186 from the Institute of Oceanology, Chinese Academy of Sciences This project was supported by the NNSFC, Grant No. 39200022.