What happens if aquatic herbicides are applied too late in the season?

When aquatic herbicides are applied too late in the season, the correct choice highlights the potential to kill fish. This is often linked to the timing of the application and the subsequent decomposition of the target vegetation. As aquatic plants die off, they decompose, leading to substantial oxygen consumption in the water. This oxygen depletion can create hypoxic (low oxygen) conditions that are harmful or even fatal to fish and other aquatic organisms.

Additionally, late-season applications may not allow sufficient time for the herbicides to act before temperatures drop, potentially leading to ineffective control of the targeted aquatic plant species. Nonetheless, the most significant risk associated with late-season applications remains the chain reaction of oxygen depletion and the impact it has on fish life, making this the most crucial reason to time herbicide applications appropriately in aquatic environments.