Prince Charles today urged consumers to match the commitment made by some leading global brands to stop the devastating effect plastics are having on the oceans.

The Prince of Wales gave a keynote speech during the Our Oceans conference, which was held at the Hilton in St Julian's.

The event was also addressed by Prime Minister Joseph Muscat, EU foreign affairs chief Federica Mogherini and EU Commissioner for the Environment, Maritime Affairs and Fisheries Karmenu Vella.

Around 40 ministers and other leaders from more than 100 other countries also took part.

The main aim of the conference, now in its fourth year, is to discuss ways to clean up and protect the oceans, and the high concentration of plastic in our waters was high on the agenda.

The Prince of Wales, who arrived in Malta on Wednesday, said plastic is increasingly found in fish caught for consumption, adding that "plastic is indeed now on the menu."

Researchers claim the sea will contain more plastics than fish, by weight, by 2050.

"The growing threat to the world's marine ecology has reached a critical point where plastics are now on the menu", the Prince told the conference.

He said the irreversible damage to the Great Barrier Reef is a "serious wake-up call" for nations. What is needed is a circular economy which allows plastics to be recovered, recycled and reused instead of created, used and then thrown away.

He pointed out that some eight million tonnes of plastic end up in the sea every year.

"For all the plastic that we have produced since the 1950s that has ended up in the ocean is still with us in one form or another, so that wherever you swim there are particles of plastic near you and we are very close to reaching the point when whatever wild-caught fish you eat will contain plastic."

Prime Minister Muscat said Malta wanted to lead by example and was embarking on a journey to actively mitigate the impact of marine litter on the ocean.

"By the end of 2019, Malta commits to recover 70% of the plastic bottles generated on our islands. We will do so by introducing a beverage container refund scheme. It will not be easy, even though we have been preparing for it. It might be controversial, but it is necessary."

"We cannot underestimate the effect that our daily actions have on our environment and how human actions can slowly destroy our natural surroundings, even something as vast as the ocean. Yet it is also those small actions that can gradually restore it back to life," Muscat said.

Speaking about how Malta has designated an area larger than the country itself as a Marine Protected Area, he said Malta has now committed itself to designate 30% of its waters as Marine Protected Areas in 2018 to ensure the protection of caves and reefs and to develop management plans for the protected areas by 2020.

We are also embarking on the establishment of a Small States Centre of Excellence that will provide practical support to government administrations of Commonwealth small states to attain the Sustainable Development Goals under Agenda 2030. 

Muscat also urged the private sector to get involved internationally, not only with countries in which they have big markets.