Well, tht would probably never happen, but if it did, you can purify salt water, its just more expensive
There would be no more coal left to use.
It'd all get used up and life would cease.
some are freshwater some are saltwater
All goldfish are freshwater.
All ground water is freshwater. But not all freshwater is in the form of groundwater. E.g. freshwater may exist in the form of ponds, lakes, rivers or ice caps.
Nothing would happen at all.
Nothing real - all measuring units are equally valid - BUT there would be a bit of human confusion.
Life wouldn't exist.
You would discover that you had superhuman abilities,and that you could most likely rule the world.(you would also be extremely smart)
All the Nasa projects would be useless,then all the investment for Nasa projects on mars would be used to help people on earth out of hunger .
This cannot possibly happen, so asking what would happen if it did happen is an exercise in stupidity.
Saltwater would kill a tetra fish! I think they are all freshwater fish and putting a freshwater fish in saltwater is a very, very bad idea.