Biteback: The Tuna debate

Written by staff reporter Friday, 09 January 2009 00:00

The huge bycatch associated with modern methods of tuna fishing is also affecting many other species. It is possible to harvest tuna in sustainable ways, and some companies – such as Sainsbury’s – ensure that all their tuna is caught using such methods.

However, a new league table compiled by Greenpeace has placed John West, the UK’s biggest supplier of tuna, firmly at the bottom. Despite filling its website with endless responsible-sounding platitudes – ‘John West only purchase fish which is caught with no harm to the marine environment’ – the truth is that it has virtually no restrictions on how its tuna is caught, and never tells consumers what methods were used.

Paradoxically, the campaign to promote ‘dolphin-friendly tuna’ has resulted in a huge increase in the amount of large pelagic species caught as bycatch. Tuna boats used to follow pods of dolphins and, when the dolphins located a school of tuna to feed on, would encircle the lot with a net, resulting in the deaths of thousands of dolphins.

When the US banned the sale of all tuna except dolphin-friendly, a new method using fish aggregation devices (FADs) was employed. These exploited the natural tendency of species such as tuna and marlin to shelter around objects floating out at sea. However, these FADs are often large steel structures anchored to the sea floor that can scan the water below and alert the fishing vessel when there is a concentration of fish. The trouble is that when the fishing boats close their purse seine net around the FAD, they net everything, which inevitably includes large numbers of sharks, turtles, rays and numerous other fish species, as well as many juvenile tuna.

Even fish that could be sold for food are still thrown back dead rather than taking up hold room that could be used for the valuable tuna. It was estimated in 2005 that around 100,000 tonnes of fish was wasted from this bycatch.

Large amounts of tuna are caught by pirate fishing vessels, as well as by companies that buy access rights from coastal developing nations, inevitably in deals that are highly favorable to the fishing companies, but the end result can leave little or nothing for local fishermen to catch.

The five species of commercially exploited tuna are skipjack, bigeye, yellowfin, bluefin and albacore. Skipjack is still reasonably abundant, although stocks seem to be declining fast in the past few years, while yellowfin and bigeye are already over-exploited. Bluefin tuna populations are close to collapse worldwide, with an 80 per cent decline in the Mediterranean. These extraordinary fish migrate huge distances, can weigh nearly 700kg and yet can accelerate faster than a sports car.

It’s time that companies selling tuna started considering the consequences of their policies. The Co-op and Marks & Spencer are at least trying, but if you want to eat tuna, best get it from Sainsbury’s. Avoid Princes, Tesco is not much better, and John West is by far the worst. Go to www.john-west.co.uk/contact-form.aspx and tell the company what you think – and it might just start behaving responsibly.