Pr. Dando et al., ECOLOGY OF GASSY, ORGANIC-RICH SEDIMENT IN A SHALLOW SUBTIDAL AREA ONTHE KATTEGAT COAST OF DENMARK, Marine ecology. Progress series, 100(3), 1993, pp. 265-271
Mats of algae are frequently washed inshore along the sandy beaches in
the Kattegat after storms and subsequently buried by sand deposition.
Sediment cores were taken in May 1991 from one such shallow subtidal
area, from which gas bubbles were being released. The organic-rich lay
er was less than 4 cm thick; it had extremely high sulphate reduction
rates, up to 1.7 mmol sulphate reduced dm -3 d-1; high hydrogen. Up to
100 mumol dm-3; methane, up to 54 mumol dm-3; and hydrogen sulphide i
n excess of 1 mM. No macrofauna were found in this quicksand area and
most of the meiofauna were confined to the uppermost 2 cm. The only me
tazoan to occur below the 6 cm zone, and down to a depth of at least 3
4 cm, was the nematode Sabatieria longispinosa. The anaerobic ciliate
Trimyema sp. cf. marinum and the anaerobic flagellate Hexamita sp. dom
inated the highly reducing, organic -rich zone at 2 to 6 cm depth; the
y also occurred below this zone together with a few specimens of Euplo
tes sp.