Britain's Prince Charles said that plastic is now "on the menu" in the fish we eat and called for decisive action as he opened a conference Thursday on protecting the world's oceans.
The heir to the British throne, a long-time champion of environmental causes, told the European Union-backed conference in Malta that ferocious hurricanes and coral reef loss are "wake-up" calls in the fight against climate change.
With eight million tonnes of plastic waste entering the oceans annually, the world must switch from "throw-away, convenience lifestyles" to a recycling economy, he said.
"We are very close to reaching the point when whatever wild-caught fish you eat will contain plastic. Plastic is indeed now on the menu," he said.
The prince pushed for a stop to overfishing by ending "perverse" government subsidies and promoting investments in sustainable ocean economies.
"The problems we face are not only enormous, they are also systemic and interrelated," he said.
These problems, he added, can only be solved through cooperation among governments, big business, multilateral agencies, scientists and non-governmental organisations.
"Decisive action is required," he said.
He expressed particular concern about warming oceans that he said have helped spawn monster hurricanes and damage coral reefs that host two-fifths of all marine species.
The prince suggested that we are no longer part of a rational civilisation "if the unprecedented ferocity of catastrophic hurricanes is not the supreme wake-up call" for fighting climate change.
In the wake of devastating hurricanes in the Caribbean and southern United States, some climate scientists see evidence that warmer ocean temperatures yield more moisture, more rainfall, and storms of greater intensity.
Charles first gave a speech on environmental issues in 1968 and has spoken out against climate change sceptics at a series of events since, including the Paris climate summit in 2015.
As part of his efforts to live a more sustainable lifestyle he has installed solar panels at two of his homes and runs his Aston Martin car on bioethanol made from "wine wastage and a cheese by-product," according to his office.
In hosting the "Our Ocean 2017" conference, the EU pledged 550 million euros ($645 million) to support a slew of measures to improve ocean health, including by reducing plastic waste and boosting marine research.