Only through greater collaboration will we be able to ensure the sustainability of global fish stocks, says Lucy Neville-Rolfe

Catches from 25% of the oceans' fish stocks are over-exploited or above the level of long-term sustainability. Yet fish accounts for almost 20% of the protein in human diets globally. So how can we ensure the recovery of major fisheries worldwide?

It's a major challenge. My view is that it is the most difficult public policy issue, in some ways more difficult than climate change, and it was the big talking point at a recent debate I took part in on global fisheries, in Davos. I came at the issue from two angles: addressing the difficulties of enforcement that flow from the lack of clear ownership and the part consumers might play.

The fisheries industry poses a unique set of challenges because there is no proper ownership system for the stocks it relies on. In some oceans there is no clear jurisdiction and, where there is, it is generally ownership of the means of enforcement, not of the seabed or the fish, making conservation especially difficult for migratory species. Common sense tells us stocks suffer in such circumstances, especially as fishermen are hunters.

To improve stocks we need international collaboration, but quotas and regulation are generally agreed by political leaders who do this by increasing the size of the cake. Where the quota for a stock exceeds the scientifically recommended level the excess is a paper fish without any physical reality and catching the excess created by these phantom allocations inevitably leads to problems down the line.

Smuggling and illegal landing are huge problems and there is also a social issue. Fishing is often vital to local communities. But unlike action to reduce CO2, which saves energy, the key players don't save money from responsible steps.

On the consumer front there is some good news, however. First, people want to eat fish. With the drive to healthy eating, especially as people get older and the value of oily fish with omega-3 is understood, demand will rise and there will be more scope for value-added lines.

Second, there is a growing body of advice to consumers to choose species and types of catch that are sustainable. Tesco and other big players try to buy their seafish from responsibly managed fisheries. Price is important to consumers, but so is information and Tesco now has labelling that highlights responsible sourcing, nutritional information, origin and catch method. And we have introduced information sheets at our counters on sourcing, sustainability, home storage and cooking.

Community fisheries are also important. For example, in the south west we have sponsored a scheme for responsibly caught sardines, sprats and scallops, which are promoted in stores in the area.

The MSC has done great work. Even so, our research shows motivation to buy sustainable fish based on the logo is below 2% and recognition low. Quality and freshness score much higher than sustainability. If consumers understood the importance of sustainable sourcing this would help to secure responsible change by governments. Retailers like Tesco can play a pivotal role.

The weak legal system and bad subsidies are problems. So we need to make it costly for fishermen and others in the supply chain to do the wrong thing, and work for urgent and co-ordinated international action in the WTO and elsewhere.

Lucy Neville-Rolfe is corporate and legal affairs director of Tesco.

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