A report revealing the true' cost of the prawn sandwich has been launched by environmental campaigners.
Squandering the Seas' has been published by the Environmental Justice Foundation, looking into the effects of prawn trawling.
According to the report, trawlers catch 10 to 20kg of marine species to obtain just 1kg of prawns in the Tropics. It said the local fish stocks and fishing grounds are heavily affected, with catches declining sharply where trawlers operate.
Steve Trent, director of EJF, said: "This waste, to feed a luxury market here in the UK and other nations, is totally unacceptable."
Meanwhile, a new prawn trawl has been designed by Seafish which could help fishermen significantly reduce the by-catch caught in their nets.
Recent trials with the new trawl off the north east of England produced not only a reduction in the number of unwanted fish, but an increase in the prawn catch.
Seafish hopes the results will encourage fishermen to take advantage of the new design.