No abstract

No abstract

No abstract

Oxic and sub‐oxic N.‐E. Atlantic sediments were examined for sulphate‐reducing activity. Oxygen and/or nitrate reduction are probably the dominant mineralisation processes in the abyssal plain sediment studied. A low rate of sulphate reduction (0.1 nmol SO2−4/ml/day) was recorded in the surface 5 cm of the continental slope sediment, together with the presence of a range of sulphate‐reducing bacteria (SRB). A higher activity of sulphate reduction (2.2 nmol SO2−4/ml/day) occurred in the continental shelf sediment which led to a small decrease in pore water sulphate and an increase in titration alkalinity. This sediment contained approx. 102–103 acetate, lactate and propionate oxidising SRB/ml. No low‐Mr organic acids were detected in these sediments. However, amendment with 75 μM acetate stimulated sulphate‐reducing activity in the shelf sediment.

No abstract