Some question whether sustainable seafood delivers on its promise

Seafood counters used to be simpler places, where a fish was labeled with its name and price. Nowadays, it carries more information than a used-car listing. Where did it swim? Was it farm-raised? Was it ever frozen? How much harm was done to the ocean by fishing it?

Many retailers tout the environmental credentials of their seafood, but a growing number of scientists have begun to question whether these certification systems deliver on their promises. The labels give customers a false impression that purchasing certain products helps the ocean more than it really does, some researchers say.

Backers respond that they are helping transform many of the globe’s wild-caught fisheries, giving them a financial incentive to include environmental safeguards, while giving consumers a sense of what they can eat with a clear conscience.

To add to the confusion, there are a variety of certification labels and guides, prompting retailers to adopt a hybrid approach, relying on multiple seafood rating systems or establishing their own criteria and screening products that way.

As of Sunday, for example, Whole Foods stopped selling seafood listed as “red” by the Monterey Bay Aquarium and Blue Ocean Institute — including octopus, gray sole and Atlantic halibut — because these species are overfished or caught in a way that harms ocean habitat or other species. The move has sparked criticism from New England fishermen, who are now barred from selling to the upscale chain. Whole Foods also sells only pole- or line-caught canned tuna, which harms fewer species than conventional tuna-fishing methods.