Microplankton ets measurements as a means of assessing respiration in the Benguela ecosystem

Abstract

Measurements of electron transport system (ETS) activity of microplankton and14C 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 other upwelling regions. Activities depended on the phase of the phytoplankton bloom and hence on the phase of upwelling. When all three parameters are integrated above die 1% light level, there is a high correlation between ETS activity and both primary production and chlorophyll a concentration. The total respiratory demand during the Anchor Station, 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 value of 0, 50. © 1994 Taylor & Francis Group, LLC.