Without oceans there would be no life on Earth - a staggering 80 percent of all the life on our blue planet is to be found hidden beneath the waves. They drive weather patterns, act as a vital source of proteins and minerals, and create over half our oxygen.
Climate change, pollution and overfishing are all taking a serious toll. In particular the loss of fish from the oceans has harmful knock-on effects, including a deterioration of water quality, oxygen depletion, and higher numbers of toxic algal blooms (rapid temporary increases in microscopic plankton levels which can poison other marine life).
Problems like coral bleaching from ocean acidification, and deaths from the ingestion of plastic waste are also increasing.
Our oceans need a break from this relentless assault. That's why Greenpeace is proposing that we protect and preserve our oceans now and for the future by setting aside swathes of the global oceans from exploitation and human activity, and allow these areas the respite they so desperately need for recovery and renewal.
We're proposing the 40 percent of the world's oceans be declared 'no take' Marine Reserves - areas where no fishing or intrusive extractive industries like oil drilling or gravel dredging are permitted. There's plenty of evidence that in ocean areas that have already been protected, threatened species are returning and there is an overall increase in the variety of species present. And in areas just outside the reserves where fishing is permitted, fishermen have recorded big increases in the size of their catch.
So it's up to us - we can plough ahead in a 'business as usual' manner and permanently damage one of our most precious resources, or we can pull back from the brink by establishing a global network of marine reserves and giving the oceans the breathing space they need to begin the recovery process.
If we don't, our oceans will die. And dead oceans means a dead planet. So do we really have a choice?
Find out more about the key threats facing our oceans:
