The consequence of nitrogen surplus in ecosystems is often eutrophication, which leads to overgrowth of algae in water bodies. Excess nitrogen, primarily from fertilizers and wastewater, promotes rapid algae blooms. This growth depletes oxygen in the water as algae decompose, creating hypoxic conditions that can kill aquatic life and disrupt entire ecosystems. Additionally, eutrophication can lead to the loss of biodiversity, harmful algal blooms, and deterioration of water quality, significantly impacting both marine and freshwater habitats.