Answer
Bacteria are heterotrophs, which consume the organic materials (e.g., carbohydrates) and the oxygen produced by the autotroph algae via photosynthesis. The algae are most efficient at producing carbohydrates and oxygen at certain UV wavelengths, so the bacteria accumulate along those wavelengths to maximize their energy sources.
Work Step by Step
The bacteria proliferate at wavelengths at which algae produce the most carbohydrates and oxygen because they feed off of these energy sources.
