
The sun rises over sand dunes that separate Parker River National Wildlife Refuge’s inland salt marsh habitat from the Atlantic Ocean. Historic ditches dug to drain the marsh for harvesting salt hay and controlling mosquitoes now cause harmful ponding. Water trapped between ditches saturates the soil, preventing oxygen from reaching plant roots. To keep marsh plants from dying, biologists dig narrow, shallow channels, or “runnels,” to allow water to drain in a more natural way.