But not all fisheries are equally threatened and asking people to stop eating fish altogether certainly isn't the answer – you will be relieved to hear!

I am enormously grateful to Coldwater Seafood to have invited me here today. I could not be more impressed by all that I have seen. I am particularly grateful for their generosity to The Prince's Trust – the donation will make a huge difference to The Trust's work here in Lincolnshire.

I am delighted to be here in Grimsby, a town and harbour intricately bound up with fish and fishing for well over a thousand years. But when my great, great, great grandfather Prince Albert laid the foundation of the Royal Dock a hundred and fifty years ago, Grimsby was only just setting out to become a major fishing port.

It is a measure of the determination and ability of the Grimsby fishermen – and all those who supported them - that, one hundred years later, in the 1950s, Grimsby was reckoned to be the world's largest fishing port. Today, things have moved on again, with Grimsby still leading the way – but this time as a centre of fish processing.

No-one here will need any convincing of the benefits of fish, from the open sea, as the healthiest of foods, nor of the ability of a thriving seafood industry to provide employment and income. But all those benefits are balanced precariously on the welfare of a wild, natural resource, just as they were a thousand years ago.

With the incredible power of twenty first century technology, it is inevitable that, sooner or later, in certain locations and at particular times, the wild resource is going to be over-exploited. And when that happens, as we have seen on the once prolific Grand Banks fishery off Newfoundland, there is no guarantee that stocks will ever fully recover. The collapse of any fishery is inevitably an environmental, economic and social disaster all rolled into one.

No-one who has seen the decline of the East Coast fisheries could possibly be unmoved by the desperate human consequences for so many families and I know that great efforts are being made to make some of the inevitable changes as bearable as possible for all those affected, and my heart goes out to them.

But these are not just issues that concern fishing communities, even though 200 million jobs worldwide do depend directly on fishing. If we can't find ways of managing these wild resources effectively, for the long term, we will all suffer, with nowhere faring worse than the developing world, where 40% of all protein consumed is in the form of fish.

But not all fisheries are equally threatened and asking people to stop eating fish altogether certainly isn't the answer – you will be relieved to hear! In addition to good science and good regulation, we need a system that harnesses the power of the consumer and provides economic incentives to well-managed wild fisheries. That is exactly what the Marine Stewardship Council does, and that is why I have been such a strong supporter of its work right from the start.

With two hundred MSC labelled products now on sale in 14 countries, it is clear that a significant number of consumers, retailers, food processors and food service providers are willing to support independent certification. It will take time for the volumes of fish from certified sources to build up, but a number of large fisheries, together representing some 3.5 metric tonnes per year, are currently under assessment – which I find hugely encouraging. And only yesterday I heard the encouraging news that four Norwegian fisheries – including one haddock and one cod stock – have decided to go through MSC assessment.

Companies here today, including Coldwater, Brakes, Marks & Spencer and The Spirit Group are using the MSC to drive more sustainable approaches to fishing. In doing so I believe they are making an investment not only in the future of their own businesses, but in a healthy and sustainable future for us all and I do congratulate them. And I hope that everyone involved with a stake in the future of seafood will join them in working with the MSC.

A hundred and fifty years ago, the coming of the railway created an entirely new market for Grimsby's fish. With the right support, I would like to think the MSC could do something similar for Grimsby's fish processors of today. If what I have seen at Coldwater today is anything to go by, with its high standards and committed management and staff, I have every confidence that Grimsby will find a secure and prosperous future.

It gives me the greatest possible pleasure to unveil this plaque to mark my visit here today.