The use of photosynthesis inhibitor (DCMU) for in situ metabolic and primary production studies on soft bottom benthos

A selective chemical photosynthesis inhibitor, DCMU (Dichorophenyl-dimethylurea), dissolved in DMSO (Dimethyl sulfoxide) was substituted for the dark incubation method commonly used to measure the oxygen consumption in metabolic and primary production studies. We compared oxygen fluxes during light incubations with DCMU and dark incubations procedure, on soft bottom benthos. For this purpose, we studied the effects of different DCMU concentrations. A concentration of 5 · 10^–5 mol l^–1 inside a clear incubation enclosure completely inhibits photosynthesis without affecting the metabolism of soft bottom benthos.