THE BENTHOS OF SOME SOUTHERN AFRICAN LAKES PART IV: THE BENTHOS OF LAGOA POELELA

Summary

The benthos of Lagoa Poelela (Mozambique) was sampled in July 1973 with a Van Veen grab. The substrates of the lake were sandy between o m and about 3 m. Thereafter sand and silt were common to about 9 m and mainly pure silt below this depth.

The benthos was mainly distributed between o and about 12 m, with very little below that depth. The faunal list comprises 19 taxa of which only nine can be classed as truly dominant benthic organisms, the remainder being only either planktonic forms with brief sojourns in the benthos or uncommon. Three forms dominate the standing stock biomass. Musculus virgilius associated with Chara between 5 and 2 m has a biomass of 2,307 g m⁻². Grandidierella bonnieri has a biomass of 0,213 g m⁻² between o and 3 m and 0,143 between 5 and 12 m. Pontogeloides latipes is most abundant in 0–3 m with a standing stock of 0,172 g m⁻². It is argued that this lake may develop either a thermocline or a halocline or both during summer, and hence the very low biomass of 0,007 8 m⁻², below 12 m.