Consuming Issues: A fishy tale: Princes' claims on its tuna tins

A television series this week showed British trawlermen tossing dead cod back into the sea and African fishermen confirming their tuna nets also snared turtles, sharks and dolphins.

While campaigners have been warning about wasteful trawling for years, the images from Hugh's Fish Fight depicted the reality stronger than any number of academic papers, quango websites or newspaper articles about "discards".

If, after watching the prgrammes, you want to help keep the oceans healthy, what can you do? Well one of presenter Hugh Fearnley-Whittingstall's messages was that British consumers rely too heavily on just three different species, cod, salmon and tuna, all of which are associated with different environmental problems: cod because it is heavily fished, making it even more absurd to throw back caught specimens; tuna because there is a large by-catch, unwittingly listed by those Ghanaian fishermen, and salmon, because three kilos of small fish are required to produce one farmed kilo.

Consumers can help by signing up the Fish Fight campaign to end discards, and by shopping more carefully.

Cod. While North Sea stocks are recovering, cod off the UK is only a fraction of its historical abundance, probably only one twentieth. Most of Britain's traditional favourite in fish-and-chip shops and supermarkets comes from hundreds of miles away, from Iceland and the Barents Sea. There is no reason to boycott cod because these faraway fisheries are well managed, but such a heavy emphasis on cod could lead to it plunging back into trouble in the future. Eating other species such as coley, gurnard, dab, flounder and herring helps relieve pressure on cod and preserve it for future generations, though you may need to visit a fishmonger to find some of them.

Tuna. Some tuna is caught by the pole-and-line method, which does not involve by-catch, but most is caught by purse seine trawlers. In a few words, purse seine nets hoover up marine life congregating around man-made rafts called fish aggregating devices (FADs), including turtles, sharks and other animals, which are usually thrown back into the water, dead. This week Greenpeace published a league table of tinned tuna. Sainsbury's, Marks & Spencer and Waitrose, which all sell pole and line caught tuna, topped the table. The purse seining Princes, responsible for a third of UK tuna sales, came bottom. Princes said on Wednesday it would drop its claim on its tins that it is "fully committed to fishing methods which protect the marine environment and marine life." Instead it will refer shoppers to an online statement about its policy on sustainability – but it will carry on purse seining. John West, another purse seiner, came second bottom. Greenpeace had ranked Tesco last, but, following Tesco's announcement this week that it will sell only pole and line-caught tinned tuna by the end of 2012, Britain's biggest supermarket was ranked fourth. The best tip here is to buy pole-and-line caught tuna: easily done at Sainsbury's, Marks & Spencer and Waitrose.

Salmon. Given that wild fish also eat small wild fish, there is no need to avoid farmed salmon, but organic salmon farms which use fish offcuts for feed, are better than conventional. There is no harm, though, in eating mackerel instead of salmon from time to time.

More generally, when shopping, the Marine Stewardship Council is a useful though not perfect indicator of whether fish has been sustainably caught.

And don't overlook British seafood, much of which is sold abroad but whichis cheap, healthy and sustainable. Look out for langoustines and mussels, to name just two.

Heroes and villians: Commons probes energy prices and RBS fined £2.8m

Hero: Tim Yeo

Mr Yeo's Energy and Climate Change Select Committee has invited Ofgem's chief executive Alistair Buchanan to a little light questioning next week. The cross-party committee says the subjects to be discussed are: gas and electricity prices, competition in UK energy markets, electricity market reform, and "Ofgem's future".

Villain: RBS Group

RBS and NatWest have been fined £2.8m for mishandling complaints. Which? summarised: "It appears that instead of taking complaints seriously RBS and Natwest have been paying lip-service to the process, delaying and inconveniencing their customers and systematically rejecting complaints they should have been upholding."

m.hickman@independent.co.uk