Atlantic cod, plaice and haddock have all been put on the endangered list by the Marine Conservation Society (MCS), which is encouraging restaurateurs to avoid using the fish.
To help restaurateurs who want to avoid serving up species with a threatened future, the MCS has set up a website, www.fishonline.org.
The MCS said a database, which grades more than 120 species from one to five, was set up in response to specific questions from small restaurateurs, consumers and retailers. The higher number denotes stocks which are overfished, vulnerable to exploitation or badly managed, or where the capture method damages habitats or other species.
Dawn Bache, fisheries officer at the MCS, hoped the site would encourage demand for more sustainable or exotic species that would give traditional stocks the chance to recover from overexploitation.
John Dyson, chairman of the British Hospitality Association's technical committee, said the site was an excellent source of information, but needed more details about the suppliers of recommended stocks. At present, he believed it would prove more useful to large companies such as contract caterers, which had more bargaining power over their suppliers.
But Tony Allan, founder of the Fish! chain, disagreed. Suppliers would, he said, be more amenable to smaller restaurants wanting smaller quantities and willing to pay a higher premium. He feared the volumes demanded by the big players could easily destroy the sustainable - and thus more limited - fishing grounds.
While all cod stocks are under pressure, the MCS said Icelandic and Faroese stocks were less critical than North Sea grounds, while haddock and plaice, which are overfished in the Atlantic, were abundant in the North and Irish Seas, respectively.
Red List - fish to avoid Atlantic cod
Atlantic wild salmon
Sea bass (trawl-caught)
Tiger prawn *
** Except from specified sources
Green List - fish to eat\ Eastern Channel Dover sole
Pacific or farmed salmon
North Sea sprat
English Channel whiting
\* From specified sources
Source: Caterer & Hotelkeeper magazine, 12 August 2004