yes there is
no
Seaweed is a living organism. It is a eukaryotic protista.
lichen
non living, since it dried.
big slimy green thing
Yes, Kelp is a seaweed. Seaweed is the common name for most marine algae. Kelp is a type of brown seaweed. See related link
No. Seaweed is actually good for a pond, but pond scum (most of the time) isn't
Seaweed is the one thing you need to eat!
No. See the 'Related Questions' for more information.
seaweed seaweed seaweed
No, kale is not seaweed. Perhaps you mean "kelp" which is a seaweed.
Turnstones eat any thing they can find under rocks/seaweed and eggs of other turnstones.