The report from the Downing Street Strategy Unit made clear the link between a healthy fishing sector and the on-shore dependent communities, and this is especially so in areas such as this, which are largely rural.

I could not be more pleased to be here in Plymouth to launch the “Invest in Fish” initiative. Rebuilding the fishing industry in ways that benefit local communities and the marine environment will not be easy, but I cannot think of a more important task for this very special part of the world. The support and involvement of the fishing industry, a major environmental group, and a major food retailer is hugely encouraging – because each of those organizations has a genuine stake in its success and I have much enjoyed talking to the members of the Steering Group a moment ago...

Now I know that the initiative will wisely start with a comprehensive consultation exercise, involving all those who have an interest in the industry and the marine environment. But I hope you won't mind if I get my own contribution in now!

And I am going to start by quoting a wise American professor of environmental economics, Professor Herman Daly, who once said something to the effect that we need to start thinking about the economy as a wholly-owned subsidiary of the natural environment. Well, in the same way, I believe we have to start treating our fisheries as a wholly-owned subsidiary of the marine environment. Which means that if we want to achieve all the many benefits of restored fisheries, we need to start by taking measures that will first restore the natural environment.

I quite understand why many people would prefer to concentrate on the fisheries, while conceding that the marine environment is quite important too. But I am afraid it does not work like that. Fish stocks will only thrive in the long-term if we have much better stewardship of the whole marine environment. So fisheries management will have to be about much more than managing (or attempting to manage) fishermen.

I am also concerned about approaches that concentrate mainly on making sure that things do not get any worse, while looking for short-term, selective gains. That seems to me to be both unambitious and a recipe for disaster. Marine fisheries could – and should - be the ultimate sustainable industry. But current methods, and the conventional management of fisheries, have resulted in a damaged and degraded environment, with serious consequences for the survival of fisheries and dependent communities.

Just to give you a couple of statistics – the complexity of the marine food chain in the North Sea halved between 1880 and 1980, and since then the rate of deterioration has increased. And more recent independent research shows that the deterioration in the Celtic Sea is also increasing, and may soon reach North Sea levels. Looking at a much longer time scale, archaeologists have demonstrated that for four and a half thousand years the average size of cod was between 80 and 100 cms. The average size of cod caught in the North Sea nowadays is about 35 cms. This is consistent with other research which shows that stocks of large fish of the main commercial species are now at around one tenth of their pre-industrial levels.

But let us be clear - no-one should blame fishermen for this state of affairs. Like the majority of farmers who adopted intensive methods of agriculture after the Second World War, most fishermen have simply responded to the economic signals they were given. In doing so, they have ensured their own livelihoods and provided us with one of the healthiest foods known to man. That is surely a matter for congratulation, rather than anything else. But this success has come at a high price. And, as the valuable recent report from the Prime Minister's Strategy Unit makes clear, the industry now faces major challenges in achieving a sustainable and profitable future.

I do not think anyone really knows the capacity for recovery of marine ecosystems or, indeed, precisely how to go about achieving that aim. But when the stakes are so high I cannot help thinking that a precautionary approach is essential.

Almost twenty years ago I put myself into rather hot water by saying that we were treating the North Sea as if it were a bottomless pit for our waste, and that it was ridiculous to delay stricter controls on dumping until we had proof of damage. I remember saying that the environment is full of uncertainty and that it made no sense to test it to destruction, which was what we appeared to be doing. Fortunately that view prevailed and the North Sea is now rather cleaner than it was. Well, I don't intend to test the Minister's patience in quite the same way today, but I do want to suggest that we need to take a similarly precautionary approach for the long-term benefit of our fisheries. One excellent way of doing that would be to start establishing a proper network of Marine Protected Areas without further delay.

There are, of course, different sorts of Marine Protected Areas, ranging from temporary closed areas for fishing, to areas – such as Special Areas of Conservation – where activities have to be ‘sustainably managed', and finally to the so-called Highly Protected Marine Areas. This is a subject that first interested me more than a decade ago, when I was asked to provide a Foreword to a book about fisheries in New Zealand. I recognize that the situation there is very different to the situation here, but the principles are the same. I am convinced that we need all three sorts of protected areas. But if we are serious about restoring the marine environment to the point where it can support larger, more robust and more profitable fisheries in the long-term, I believe we need substantial areas where all extractive activities are prohibited, and where other significant human pressures are minimized.

At the moment England's coastal waters have only a single area – of 3.3 square kilometres, around Lundy Island as it happens, which is protected in this way. Around the world there is ample evidence that such highly protected areas provide rapid benefits for sedentary species, but it is becoming increasingly clear that more mobile species also benefit. The resident population builds up a reservoir of reproductive capacity, which is then gradually exported to adjacent areas and further afield.

The example I would draw to your attention is the Georges Bank of the Gulf of Maine in the USA. In 1994, following the virtual collapse of the fishery, 17,000 square kilometres, which is about one quarter of the total area, were closed to fishing for bottom-dwelling species and to methods that might cause damage to the environment. After five years the environment was clearly recovering, and the species decline had been reversed. The most dramatic gain was by the scallops, with densities nine to fourteen times greater inside the reserve than outside. But even cod stocks were found to be increasing, with one Cape Cod fisherman reporting that he was travelling less than half the distance and catching nearly twice as much cod as he did before the closures. Similar effects have been observed off Cape Canaveral in Florida, where security considerations created an inadvertent highly protected area, with noticeable benefits for the surrounding fisheries.

I recognize that the idea of establishing a network of such Highly Protected Marine Areas will not be popular in many quarters, and that the absolute benefits are not quantifiable. But if we are trying to take a long-term view I believe it makes sense to look seriously at setting aside areas for recovery in this way. We are fortunate that the natural world has great resilience, and remarkable powers of recovery, but we do have to allow sufficient respite for that to happen.

Ladies and Gentlemen, I believe that the “Invest in Fish” initiative offers unique possibilities. Bringing together the wide range of local people and organizations with interests in fisheries and the marine environment to look for new solutions is a brave and commendable initiative. I am sure the process won't be straightforward and that there will be a need for a good deal of ‘give and take' on all sides, but the very fact that this initiative exists shows just how progressive and forward thinking this area of the United Kingdom is – you understand about long term sustainability and you know how to make an investment in the future. The history and culture of this part of the country, more than perhaps any other, is intimately bound up with the sea, and a sustainable marine harvest, and it is unthinkable that the same cannot be true of its future.

The report from the Downing Street Strategy Unit made clear the link between a healthy fishing sector and the on-shore dependent communities, and this is especially so in areas such as this, which are largely rural. For too long now we have seen the difficulties which have faced agriculture resulting in young people who once would have been engaged in agriculture leaving for jobs elsewhere. The “Invest in Fish” initiative, if successful, will, I hope and pray, stop a similar exodus from our precious coastal communities, which are as much a part of our natural heritage and culture as our small, family farmers who provide the social and environmental backbone of our countryside.

People visit the countryside because it is beautiful and they treasure the way of life. Similarly, tourists come to fishing villages and towns because of their unique charm, character and richness of history, which have been built up over centuries. This is something to be treasured and I know that the goodwill and commitment which I have witnessed today from those involved in “Invest in Fish” will pay rich dividends for the whole of the South West of England, and set an example to be followed across the rest of the country. I can only wish you every possible success.