Video report by ITV News Royal Editor Chris Ship
Prince Charles has said he's speaking out about the threat to the world’s oceans because he worries about his own grandchildren - and grandchildren everywhere.
The prince has been speaking to ITV News in Malta where world leaders and scientists are attending the Our Oceans conference.
He has urged the world to turn its attention to the failing health of the oceans or risk our own survival.
Asked if he worried about the world the generation of Prince George and Princess Charlotte will inherit, he said he was doing it for everyone’s grandchildren.
Over-fishing, plastic pollution and acidification are all combining to threaten our own survival, he said.
And he warned that plastic in the oceans is now in the human food chain.
Every year eight million tonnes of plastic enter the sea and he urged consumers to think about buying drinks and water in single use plastic bottles.
Prince Charles releases a turtle back into the wild
Evidence of the threat from the oceans has already been seen in recent storms, he said, such as the hurricane which devastated parts of the Caribbean and Florida.
We risk "ever more damaging and terrifying storms", he warned, and the ferocity of hurricanes such as Irma and Maria were a "wake up call" about the threat of ocean warming.
The delegates have been examining the importance of - but also the threat to - what they call the Blue Economy.
The term refers to the economic life we get from the seas.
The water, which covers two-thirds of this planet, is the seventh biggest economy.
If the oceans of the world were a single country they would have a seat at the table of the G7 - the group of the world’s biggest economies.
Future generations - such as the one to which his grandchildren belong - will not forgive us, said the Prince, "for destroying the viability of the natural world that is our ultimate sustainer?"