Chemical and microbiological aspects of acoustically turbid sediments.

The methane concentrations within both Holyhead harbour and Western Irish sea sediments were consistent with the hypothesis that methane was the major component responsible for the acoustic turbidity, which is in agreement with Anderson and Hampton (1980 a) and Vilks and Rashid (1977). Microcosm experiments indicate that, for Holyhead harbour methanogenesis may be the major contributor to the methane pool held within the sediment. Furthermore sulphate-reducing bacteria, although natural competitors for the most probable subtrates of methanogenesis, may be limited in their activity by sulphate concentrations at the depths where methane is being produced