PRELIMINARY-ANALYSIS OF BACTERIAL NUMBERS AND BIOMASS IN LANGEBAAN LAGOON

Water samples taken down the length of Langebaan lagoon reveal a decline in bacterial numbers from Saldanha Bay to the head of the lagoon, with a parallel decline in suspended particles. Bacterial biomass (x 43, 27 mg.m−3) was comparable to zooplankton biomass. Intertidal samples from different sediment types showed an increase of bacteria towards the southern tip of the lagoon, with decrease in particle size and increases in percentage mud and percentage organic material. Bacteria comprise only a small percentage of the organic pool, but their biomass ranges from 16 to 232 mg (dry weight) per kg of wet sediment. This approximates a mean of 14, 2 g (dry weight) per m2(range 1, 32 to 25, 74): comparable to the biomass of benthic macrofauna. Considerable seasonal variation occurs in the organic pool. © 1979 Taylor & Francis Ltd.