Which type of pollution is primarily caused by excess nutrients from fertilizers entering a water body?

Nutrient pollution occurs when excessive amounts of nutrients, mainly nitrogen and phosphorus from fertilizers, enter waterways. This influx promotes excessive growth of algae and aquatic plants, a phenomenon known as eutrophication. Eutrophication depletes oxygen levels in the water as decomposing algae consume the oxygen, leading to hypoxic or anoxic conditions that can severely harm aquatic life. Nutrient pollution is a significant environmental concern as it affects water quality, biodiversity, and the overall health of aquatic ecosystems.

Thermal pollution relates to changes in water temperature caused by industrial discharge or other activities, impacting aquatic habitats. Chemical pollution encompasses a broader category that includes harmful substances like heavy metals or toxic chemicals but does not focus specifically on nutrient overloads. Biological pollution involves the introduction of invasive species or pathogens, which is distinct from the effects caused by excess nutrients. Therefore, the emphasis on nutrient overload and its ecological consequences makes nutrient pollution the correct classification in this scenario.