Which is NOT one of the major objectives of preventative aquatic weed control?

The objective of preventative aquatic weed control is primarily focused on managing and mitigating the factors that promote the growth of aquatic weeds. Increasing nutrient levels would actually contribute to the problem, through promoting the growth of various aquatic plants and algae. This goes against the intended goal of maintaining a healthy aquatic ecosystem and preventing weed spread.

On the other hand, eliminating nutrient sources is critical because excess nutrients, particularly phosphorus and nitrogen, can lead to algal blooms and rampant weed growth, compromising water quality. Prevention of weed spread is also a key objective, as controlling the spread of existing weeds protects areas that are still clear and prevents the need for more extensive control measures later. Deepening of water bodies is sometimes a management technique to enhance flow and reduce sedimentation, which can also assist in controlling weed growth. However, this practice is not generally categorized as a major objective of preventative weed control. Therefore, increasing nutrient levels stands out as not aligned with the goals of preventative aquatic weed management.