Most waterfowl hunters know, ducks can be primarily vegetarian or carnivorous. Many species eat both plants and animals.
The ratio of plant to animal consumption depends on the habitat, food availability, and season.
I will focus on plants in Arabian marshes and wet lands; important to duck's and geese and provide identification of the various species world wide.

for more information about wetland plans
http://www.duckcentral.com/aquaticplants1.html