AS COLES and Woolworths jostle for first place in the seafood sustainability stakes, a former fisheries scientist has slammed a consumer fish guide published by the Australian Marine Conservation Society.

Nick Ruello, a consultant with the Fisheries Research and Development Corporation, says the society's Sustainable Seafood Guide "is seriously flawed, misleading and not really helping consumers find sustainable seafood at all''.

The society, a charity whose patron is the writer Tim Winton, produces the booklet and online guide assessing the relative sustainability of more than 100 Australian species of fish and other seafood.

The guide uses traffic light symbols for ''Better Choice'', ''Think Twice'' and ''Say No'' to advise on what to buy and what to eat. It assesses Australian and imported fish species, including canned seafood, commonly found at fishmongers, supermarkets, fish and chip shops, and restaurants.

But Mr Ruello said its criteria were too general, not objective or quantifiable, and were focused on species rather than an individual fishery or particular aquaculture operation.