Should we engineer our offspring into mermaids

So that we can use the ocean as well as land? Seems like the land is going to get crowded pretty soon.

This is meant to be slightly funny...I'm not entirely serious.

Why stop at mermaids? We need to engineer our offspring into mermaid/bird/astronaut/cyborgs!! Future generations will rule the universe as super human mermaid things!! All thanks to our great minds :)
Also make some sort of land shark maybe? Cuz we could ride our land sharks into space or something

But the radioactive water will be combined with the polluted water, and plus the salt/fresh water!Think about it? This could be a disaster . That's why all the spaceships are taking off to find a new planet.