David - it should be read "dead" sea not red!
My brain was on idle this AM, I guess before I was fully awake. I have paddled in the Dead Sea. It is just as described. Can't get under the surface at all.
A comment - in the mining we use bacteria to catalyse leaching of copper (and now uranium and nickel)from piled up ore. The mines in Chile can be quite arid and acid consuming; consequently, salt concentrations can be quite high in the leach solutions (mainly sulphates though) But some mines do have moderately concentrations of chlode and nitrate (which are toic to the bacteria). These mines experiened por bacterial growth. But by careful acclimatization of the bacteria production/leacheing was regained.
Also there are is company that claims that it has cultured bacteria from deep sea vents. These bacteria at atmospheric conditions are claimed to be tolerant of hypersaline solutions as well.
Fascinating comment. it shows how flexible life can be in various environments.