Sir, In response to Hugh Fearnley-Whittingstall's recent Fish Fight campaign on Channel Four, there is no quick fix for the world's tuna fisheries.

True conservationists understand that sustainability will come from ­eliminating threats such as illegal fishing, and a lack of ­enforcement of compliance with conservation measures.

UK retailers and processors have been pressured to provide only pole-and-line caught tuna. However, it is possible to buy unsustainable pole-and-line tuna if small, non-targeted tunas are taken from stocks that can't support the added pressure, if some of the catch is wasted due to poor fish handling or if a vessel's carbon emissions aren't understood, if the stock fished itself is not properly managed.

If we buy into such a simple myth today about tuna, the species won't be any further down the path towards sustainability.

Susan S Jackson president, International Seafood Sustainability Foundation