Residents in a lakeside community can most effectively prevent the lake from becoming a dead zone by **stopping the use of fertilizer on their lawns**. Fertilizers contain nutrients like nitrogen and phosphorus that can runoff into the lake when it rains, leading to excessive algae growth. This process is called eutrophication and can result in oxygen depletion in the water, causing fish to die and turning the lake into a dead zone.
By stopping the use of fertilizers on their lawns, residents can significantly reduce the amount of nutrients entering the lake, thus helping to maintain a healthier aquatic ecosystem. This action can prevent algae blooms, improve water quality, and ultimately protect the fish population in the lake.
Limiting recreational fishing or discontinuing boating activities may have some benefits in reducing direct disturbances to the lake, but the primary cause of the problem in this scenario is likely the nutrient runoff from fertilized lawns. Mowing the lawns more frequently, while helpful for overall lawn health, would not directly address the issue of nutrient pollution from fertilizers.
