Great Duckweed
Spirodela polyrhiza
Size: to 0.1"
Habitat: floating free at surface
Notes: Among the smallest seed plants; important food for many waterfowl.
All manner of concrete, steel, and stone rubble from dredging, demolition projects, and other construction is used as artificial reef materials. This material is generally available at very low cost or free from construction companies who are more than happy to get rid of it. Transportation costs determine where this material is used by the Reef Program.
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