Because seaweeds absorb water and nutrients from the cell on the surface of their entire bodies.
The seaweed get nutrients from the sea water to live.
i depends some seaweed live under water some on rocks but they mostly live near the beach
they both live in the water
Seaweed such as kelp.
It floats or connects to rocks by the surface.
Seaweed do not have to live in water all the time - think of inter-tidal periods when they are not in the water. Only some kinds of moss live in the water. Many kinds of mosses never live in the water - but do tend to live in a damp environment. The underlying concept to think about is dessication.
Because they have adapted to living in salt water.
It's SEAweed
Look up Susswassertang on wikipedia. Freshwater plant whose name means freshwater seaweed. Yes, I live on a lake and we have A TON of seaweed
Plant+water=seaweed
eleodia duck weed
It all depends on what type of seaweed it is. The type of seaweed (ie colour, parts some have and others don't, size) determines where it can live without being harmed. For example, if the seaweed is strong, it can live in very rough, wavy areas. If it is not, it could live on a beach or a rock, close to the water. So basically there are many places seaweed can live; a rock, the beach, floating on the water, deep under the sea. It all depends on its strengths and/or weaknesses it may obtain.