What potential problem can arise if fertilization is halted after being previously applied?

When fertilization is halted after previously being applied, one potential issue is that aquatic weed problems may worsen. This occurs because the nutrients provided by fertilizers can stimulate the growth of both desired and undesired vegetation. When nutrients are cut off, the established aquatic weeds may not immediately die off, but rather have a competitive advantage due to their ability to withstand stress. This can result in a situation where weeds can proliferate even more in the absence of nutrient competition, leading to increased biomass and further ecological imbalance.

Continuing to apply nutrients, when necessary, can help maintain a balance among the aquatic plants, preventing any single species from dominating. A well-managed nutrient regime supports healthy aquatic environments where beneficial plants can thrive alongside regulated weed populations. Stopping fertilization suddenly can disrupt this balance, exacerbating the issues with invasive or problematic species that could outcompete desirable native vegetation in the long term.