Drift Them Away

With the hydras hunted out of the area, the drifter population in the cascades to the west is on the rise. Egg sacks are making the water murky and undrinkable, and the drifters are becoming very territorial. We must ensure that the reintroduction of the hydras will succeed. We need to cull the number of drifters and clear some of their egg sacks. You look like someone capable of doing this task. Will you help me?