July 31 (Reuters) - Amazon.com ( AMZN ) was sued on Friday by consumers who accused the retailer of misrepresenting the environmental benefits of seafood sold on its platform, a practice known as greenwashing.

In a proposed class action in Seattle federal court, consumers said labels containing phrases such as "dolphin safe," "responsibly sourced," "sustainable," "wild caught" and "MSC Certified Sustainable Seafood" misled them into believing Amazon's ( AMZN ) seafood sourcing causes minimal harm to oceans and the environment.

The consumers called such representations unsubstantiated or materially false because most fishing vessels are not publicly tracked, and some vessels obscure their whereabouts by disabling electronic devices known as transponders. They also said at least one-fifth of imported wild-caught seafood is not responsibly or sustainably sourced.

"Amazon ( AMZN ) nevertheless markets the greenwashed seafood products using broad sustainability messaging without providing disclosures necessary to prevent consumer deception," the complaint said.

The Seattle-based company is the second-largest U.S. grocer with more than $150 billion of gross sales in 2025, Chief Executive Andy Jassy said on an April 29 conference call with analysts.

Amazon ( AMZN ) and lawyers who represent it in other consumer class actions did not immediately respond to requests for comment.

The company faces frequent lawsuits over products sold on its platform, including by outside sellers.

BUMBLE BEE, CHICKEN OF THE SEA, STARKIST

The lawsuit targets dozens of tuna, salmon and other seafood products under brands including Bumble Bee, Chicken of the Sea, StarKist and Amazon's ( AMZN ) own 365 by Whole Foods Market.

Plaintiffs led by Madeleine Rogow of Los Angeles and Adam Sorkin of Chicago said they would not have bought or would have paid less for their seafood had Amazon ( AMZN ) disclosed its "true sustainable nature."

The lawsuit seeks compensatory damages, punitive damages and restitution for people in the United States for Amazon's ( AMZN ) alleged violations of Washington consumer protection laws.

The respective parents of Bumble Bee, Chicken of the Sea and StarKist - Taiwan's FCF, Thai Union Group and South Korea's Dongwon Industries - are not defendants in Friday's lawsuit.