An EEZ is an area along a country’s coast (up to 200 nautical miles seaward) where that nation has sovereign rights to the natural resources (e.g. fish). Within an EEZ, a country makes its own rules that others must follow. Behind all these decisions is sound science, though. A nation has to make sure that any fishing they allow does not deplete stocks—it must be sustainable. The coastal nations have all agreed to support healthy oceans and food security while balancing their own economic needs. An EEZ has to be proactively created—it’s not automatic. They have to go through a process to have it established. It requires exact measurements, which is difficult because coastlines change all the time, from sea level rise or storms. Once established, then it is placed on maps so others know the boundaries. Outside an EEZ is termed the High Seas.