Many bodies of water are surrounded by vegetation. The plants that grow around the water can absorb the harmful toxins from pesticides and fertilizers that are emitted from agricultural runoff. This can cause the vegetation to die. Vegetation can also be depleted from livestock consuming it. When there is not enough vegetation surrounding the water, pollutants are more likely to enter the water, and erode the banks of stream, rivers, and lakes. This is very harmful to the ecosystems in the water.