But as you say: except for the dead sea. In my mind, these new seas would have a steady influx of salt water, but only sweet water would evaporate out of them.

But as you say: except for the dead sea. In my mind, these new seas would have a steady influx of salt water, but only sweet water would evaporate out of them. And since I don't see the mechanism by which salt would get sequestered or removed from these bassins, I'd also guest their salt concentration would rise quite quickly. Of course, it might still be interesting to have a huge water surface in the area that effectively serves as a rain generator, but it might not be the same thriving ecosystem we imagine when we say "ocean".