What happens as algae die and decompose after a bloom?

When algae die and decompose after a bloom, a variety of processes occur in the aquatic environment. One of the significant aspects of this decomposition is the release of nutrients back into the water column. As algae break down, they release nutrients such as nitrogen and phosphorus, which can actually benefit other aquatic plants and lead to additional growth. This nutrient cycling can sometimes result in further algal blooms if not managed properly.

In addition to nutrient release, the decomposition process also contributes to changes in water quality and can produce various odors. However, the dominant and immediate effect during decomposition is the enhanced nutrient availability in the ecosystem, which is critical for the growth of other organisms.

The presence of a sewage-like odor can occur due to anaerobic decomposition, but it is primarily a result of specific bacterial action rather than a direct and primary consequence of the algae's death itself. Therefore, the focus should be on understanding how nutrient cycling plays a vital role in the aquatic ecosystem following an algal bloom and subsequent die-off.