Coastlines are part of ocean that act as the borded line of that sea.
A coastline is the land that borders any body of water, but mostly oceans, seas, etc.
I think WE control coastlines, because we put rubbish in the sea, that could be recicled! Actually, the answer is both. The coastline controls us in the sense that it determines where we can build...
China's coast is more communist
Maine coastline is 3500 miles - NJ is 125 miles Maine coastline is rocky, the water coloderNJ coastline is sandy and the beaches have warmer water