Question

What role do algae and aerobic heterotrophs play in setting O2 abundance in an oligotrophic lake?

Answer 1

Algae play a major role in producing oxygen in any lake because they are photosynthetic organisms and in the process produce oxygen which is essential for survival of aerobic heterotrophs which feed on algae. In an Oligotrophic lake the algal population is less and hence,making the water nutrient deficient.

The role of aerobic heterotrophs in setting O₂ abundance is that these organisms feed on algal biomass and thereby keep the algal population in control which is essential for oxygen to be present in dissolved form in water.Otherwise, if the algae growth increases the bacterial population will increase and this will lead to a decrease in dissolved oxygen present in the water because as the algae reaches its senescence stage aerobic bacteria will start to oxidize it resulting in depletion of oxygen.