[Lewis Thomson (OP)]

Donald has sent in this question to TNS.

"It is uncontested that liquid water is necessary for life. It is similarity necessary for salt to be present. In fact, the cellular membrane maintains a range of ionic/electrical potential that drives life that is totally dependent on salt, the sodium-potassium pump (Na-K pump). What does this tell us about the early oceans salinity?  What does this suggest about extra-terrestrial life? And where are plants growing on land getting their salt? (Like the massive tree growths in mountains)."

Leave your thoughts in the comments below...

[evan_au]

It is uncontested that liquid water is necessary for life

I would contest it.

Just because every form of life we have recognized on Earth requires water, does not imply that all life in the universe is based on water.

The surface of 1 planet in the "Goldilocks Zone" is not a very good sample of the universe.
- Many planets are too hot or too cold for liquid water to exist on the surface
- If life exists there (we haven't identified any cases as yet), it probably would not be based on water

[Bored chemist]

"How important is salt in the ocean?"
To whom?
The ocean wouldn't mind if all the salt disappeared.
Most plants are a good deal more dependent on potassium than sodium.

[Pseudoscience-is-malarkey]

"How important is salt in the ocean?"
To whom?

God.