MICROPLANKTON ETS MEASUREMENTS AS A MEANS OF ASSESSING RESPIRATION INTHE BENGUELA ECOSYSTEM

Measurements of electron transport system (ETS) activity of microplank ton and C-14 primary production were made during an Anchor Station in St Helena Bay in March 1987 and a cruise off Namibia in September 1988 . ETS measurements for the Benguela are similar to those recorded in o ther upwelling regions. Activities depended on the phase of the phytop lankton bloom and hence on the phase of upwelling. When all three para meters are integrated above the 1% light level, there is a high correl ation between ETS activity and both primary production and chlorophyll a concentration. The total respiratory demand during the Anchor Stati on, from microplankton, mesozooplankton and bacteria, ranges from 1,0 to 3,5 g C.m-2.day-1 and the R:P ratio from 0,24 to 0,75 with a mean v alue of 0,50.