It actually [b][i]cannot[/i][/b] get any more salty. Assuming it's sodium chloride (NaCl), only about 188,000 Mg/L can go into solution, anything over that just precipitates out as salt crystals. That's assuming the temerature is also high enough to allow for that much chloride to go into solution. It could go higher with a different salt such as ZnBr, which would roughly weigh about 22 lbs/gallon but it'd be so hygroscopic that just the moisture in the atmosphere would be enough to sustain the sea at a nominal size.