Hugh Fearnley-Whittingstall's new fishing campaign appears to have scored an early hit. How important to you is sourcing and sustainability when you buy fish? • Livechat: Hugh will be on WoM on Wednesday lunchtime

Hugh Fearnley-Whittingstall is feeling pretty optimistic this afternoon. His Fish Fight campaign has scored a major victory the day before the first TV programme highlighting it is broadcast; Tesco has announced plans to switch to 100% pole and line caught fish for its own brand canned tuna. Given the supermarket's market share and the fact that the UK is the second largest consumer of tuna in the world, this is significant, as he told me:

I'm thrilled that Tesco have made this decision. It's a huge ecological gain for the international tuna industry. I congratulate Greenpeace for campaigning so vigorously and passionately on this issue, and I'm delighted we were able to play a role by working with Greenpeace and challenging Tesco directly in our Fish Fight shows for Channel 4. But I've no doubt in the end they've decided this was the right thing for their customers, their brand and for the environment. They are the biggest fish retailer in the UK so there will be real benefits to the marine environment from this decision.





Hugh's Fish Fight, a Channel 4 mini-series which tackles some of the problems that decades of overfishing have caused starts tomorrow night. The dire situation in our seas won't be news to anyone - campaigners and journalists have been fighting and writing about it for years, but achieving change has been a struggle.

Public concern has never really been harnessed in the way that outrage over factory farming was, despite efforts by the likes of Charles Clover. Do we care less about cold fish than chickens? Perhaps, but almost everyone cares about the fact that stocks are in steep decline; in a study by the Seafood Choices Alliance, 79% of European consumers said (pdf) the environmental impacts of seafood was an important factor in deciding what to buy. And Greenpeace campaigner Joss Garman points out that other supermarkets, such as Sainsbury's, had already switched to 100% pole and line caught tuna because consumers do care; they just expect retailers to take the responsibility and offer the right thing.

There are several reasons this issue has failed to capture the public's imagination. We're fiercely attached to our white fish and chips in the UK, and the fishing industry is largely invisible, being most active miles out at sea or on inaccessible fish farms. But the biggest obstruction is probably the complexity - the whole issue is horribly bewildering. As Garman said to me, "cod is OK from this ocean but not this ocean, tuna's OK if it's this species, but not this species." And then there is the Byzantine and very unsexy Common Fisheries Policy.

So Fearnley-Whittingstall and others have taken a straightforward approach and launched a campaign on three very accessible fronts. The first show, which airs tomorrow night, deals with the issue of discards, a product of the quota system that restricts the number of any one species that can be caught and which forces fishermen to throw surplus fish over the side of the boat. As explained by the Sun - "BRITAIN'S fishermen are forced to throw nearly half of their haul back into the sea DEAD thanks to ridiculous EU laws."

The message is simple, as is the first goal; pressurise politicians to make discards a thing of the past. The other two programmes examine aquaculture by focusing on salmon farming; and the practice of catching tuna by purse seining, using huge nets that lasso entire schools of fish, and, disgracefully, countless other species of marine life.

Tesco features prominently in the latter, echoing the farmyard fight Fearnley-Whittingstall had with the retail giant a couple of years ago over his Chicken Out campaign. The company had previously committed to using pole and line caught fish in just 10% of its own-brand tinned tuna in November, an effort which had it ranking pretty low on Greenpeace's tuna league table, and behind rival supermarkets. Their decision to up that to 100% comes as Greenpeace get ready to present their league tables to the industry, tonight. This is what the supermarket had to say about their change of policy:

We will be progressing to 100% pole and line sourced tuna on our own brand canned tuna by the end of 2012, during which time we will be working to ensure that this can be achieved in a sustainable way that guarantees the quality and traceability of the product. We've been moving in this direction for some time

Fearnley-Whittingstall is keen that Greenpeace, who have been plugging away at this for such a long time, are given the credit they deserve. It seems likely, though, that memories of "Chickens, Hugh and Tesco Too" played a large part. It's promising that there's been such a significant change made already. Will you be watching? Hugh will be live here on WoM on Wednesday, so come back with any questions for him then.