The algal biology of a tropical montane reservoir (Mlungusi Dam, Malawi)

Abstract

The relationships between population changes of planktonic and bottom living algae and major environmental factors are reported for a small tropical reservoir and its inflow stream. Changes in algal crops were largely determined by water flow. The water had levels of dissolved ions comparable with those of rain but maintained large crops of mat-forming algae, particularly Spirogyra sp. This was attributed to an ability of this species to absorb nutrients at low ambient levels while being able to build up a large crop size as a result of its growth-formresistance to displacement by water movements. Aspects of the biology of benthic algae are discussed in relation to their crop sizes.