A survey of the potential waterfowl management areas of eastern Virginia, 1949

From general observations while making this survey the conditions which seem to limit the production of duck foods in the Virginia marshes are salinity, type of bottom, and tide fluctuation. The marshes that are high producers of duck foods all have a low salinity, soft muck bottoms that are covered by water except at the lower stages of the tide. On the other hand the low production marshes have a high salinity, hard bottoms that are only covered with water during the latter stages of the high tide.