Water Level Manipulation
Seasonal drawdowns are vital to the health of wetlands. Ponds bottoms must dry out periodically in order to stimilate healthy aquatic plant growth, which in turn supports the invertebrate population that larger animals (like fish, ducks and shorebirds) depend on. Water level manipulations can also be used to create favorable conditions for different wildlife species when they are most needed. For example, newly exposed mudflats and shallow water along the pond's edge are the best feeding areas for migrating shorebirds. At least one Refuge pond is drawn down in April and August for the peak of shorebird migration. Other ponds are left in permanent deep water to support a fishery for nesting bald eagles, osprey, and other fish-eating birds.