What does biochemical oxygen demand (BOD) indicate?

Biochemical oxygen demand (BOD) is a critical measurement used to assess the amount of dissolved oxygen required by aerobic bacteria as they decompose organic matter in water. In practical terms, a high BOD indicates a high level of organic pollution, which means that bacteria will consume a significant amount of oxygen while breaking down this organic material. This, in turn, can lead to decreased oxygen levels in the water, which is detrimental to aquatic organisms that rely on oxygen for survival.

Understanding BOD is essential for managing water quality, particularly in freshwater systems, as it provides insight into the health of the ecosystem and helps gauge pollution levels. Higher BOD can lead to hypoxic conditions, where oxygen levels fall below what is necessary to support aquatic life. Therefore, BOD serves as a crucial indicator of organic pollution and the potential impact on aquatic ecosystems.