Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. IV. Bacterial and Fungal Studies

Abstract

Bacterial communities in Lake Macquarie show several peculiarities including the paucity of cellulose digesters and agar digesters, and the presence at times of anaerobic sulphur bacteria in waters containing considerable oxygen.

The E_h of the lake bottom is frequently positive, negative potentials being recorded from decomposing Zostera patches and from the microbially rather inert blue muds. The latter show little or no active sulphate reduction, though Desulphovibrio may be present. Photosynthesis controls the pH on the sea-grass flats, values as high as 9.7 having been recorded off Swansea flat on a sunny afternoon.

Bacterial populations are relatively low, especially in the muds, and there is no marked seasonal variation.

Contamination by faecal pollution of the lake waters could not be demonstrated, either during the summer holiday season or during a typhoid epidemic at Swansea.