The Prince of Wales has warned of the "dire social and economic consequences" of failing to manage the world's fish stocks sustainably.
His Royal Highness, known as the Duke of Rothesay in Scotland, spoke of the need to improve knowledge of marine ecosystems as he addressed the sixth World Fisheries Congress in Edinburgh today.
He established the International Sustainability Unit (ISU) to build consensus on how to resolve some of the key environmental challenges facing the world.
The ISU's marine programme has looked at ways to manage fish stocks more sustainably to ensure there are more fish, more jobs and better economic returns.
The Prince told an audience at Edinburgh International Conference Centre that there was a "direct link" between the health of ecosystems and food security.
"It is a serious social and economic issue," he said.
"If fish stocks fail, then the social and economic consequences will be dire.
"Just think of all those thousands of coastal communities in Africa and around the world whose livelihoods and futures depend on fish ”“ Where will they go? What will they do?"
The Prince said there was a disparity between how much was known and how much should be known about the state of fish stocks.
"I am no expert, but it does seem to me that, under these circumstances, our chances of keeping stocks healthy, and oceans thriving so they can continue to maintain food security, are going to be severely compromised unless we dramatically - and I would suggest, rather urgently ”“ improve our knowledge," he said.
The Prince went on to warn that even the British tradition of fish and chips could disappear unless action is taken.
"I remember one occasion buying fish and chips from a shop in Inverness," he said.
"It never occurred to me then that I was eating food that had such a reliance on how we treat a wild natural resource."
The World Council of Fisheries aims to encourage and promote sustainable management practices, excellence in fisheries research and the wise use of fishery resources.
The congress is held every four years, with the last one taking place in Yokohama in Japan in 2008.
The Prince, who arrived in Edinburgh today by train, was greeted by the Scottish Government's Environment Secretary Richard Lochhead as he arrived at the conference centre.
Following his speech, The Prince visited Marine Scotland's research vessel Scotia in Leith Harbour.
He viewed the facilities on board and met fish and chip fryers and representatives from leading fish wholesale companies.
Speaking at the conference, he said he was "delighted that some pioneering fish and chip shop owners are making the connection" between how fish was harvested and how much would be left in the ocean to catch next time.
"The simple fact is that fish and chip shops rely on there being plenty more fish in the sea, and that is only going to be the case if we take care of fish stocks now and plan for them to be there long into the future.
"If their businesses are to remain viable in the long term, fisheries management, accompanied by sound science, really matters to them too."
The Prince met the winner and runner-up of the 2012 Young Fish Fryer of the Year Award, Zohaib Hussain and Carlyn Johnson, during his visit to the Scotia.
Meanwhile, The Duchess of Cornwall attended a service to celebrate the completion of the restoration programme of Rosslyn Chapel in Midlothian.
Her Royal Highness, who is known as the Duchess of Rothesay in Scotland, toured the historic building and met staff, supporters and local schoolchildren at a reception, before unveiling a plaque to commemorate the opening of the new visitor centre.
The service within the chapel included hymns sung by children from the National Youth Choir.
The Duchess, dressed in a grey coat with tartan trim, was also introduced to primary seven pupils from Roslin primary school, who were dressed in traditional medieval costumes and who act as chapel guides when children from other schools visit.
She later met stone conservator Lauren Jackson and sculptor Derek Cunningham, who have worked on the painstaking restoration of the building.
Built between 1446 and 1484, the chapel is covered with carvings of individual figures and scenes.
It has been deluged with visitors since it featured in Dan Brown's novel the Da Vinci Code and a film of the book starring Tom Hanks and Audrey Tautou.
The chapel has undergone a £10 million conservation programme which involved the construction of a large steel canopy over the whole building to keep out the rain.
It was removed after the completion of major roof works while conservation work has also been carried out on the external stonework and stained glass windows.
The restoration of the outer stone work is expected to be completed in December.