The air bladders would hold the main stem of the weed erect, Seaweed, being a shallow water plant, would be able to have more of it's leaves struck by the sun.
Plant+water=seaweed
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.
The seaweed get nutrients from the sea water to live.
Yes, Kelp is a seaweed. Seaweed is the common name for most marine algae. Kelp is a type of brown seaweed. See related link
Seaweed grows under water by absorbing the minerals and nutrients from the water. They also get the sunlight that reflects through the water since they are plants.
Yes, "shallow" is an adjective. It is used to describe something that has little depth, significance, or understanding. For example, a shallow lake, a shallow person, or a shallow conversation.
They live in shallow sea water
Mostly above water where you can find seaweed is the botton of the ocean.
Seaweed does not breathe, instead it respires by gaseous exchange through water
The water in the lake was very shallow
It can be shallow or deep.