Eastside residents may have noticed a large airship gliding low above rooftops early on Wednesday morning. The green blimp, which carried the message “Costco: wholesale ocean destruction,” was part of a campaign by environmental advocates Greenpeace to draw attention to decimated fish species.

Greenpeace’s 2010 Taking Stock campaign is targeting Issaquah-based retailer Costco, and seven other large supermarkets, in an effort to make their seafood purchasing and selling practices more sustainable.

Greenpeace claims Costco continues to stock “red list” species, fish which are threatened by overfishing, such as Alaskan pollock, Atlantic cod, Atlantic salmon, orange roughy, South Atlantic albacore tuna, sword-fish, and yellowfin tuna.

According to Greenpeace’s report on supermarkets that support sustainable fishing, Costco had repeatedly refused to respond to Greenpeace’s questions about its seafood policies and practices.

“Costco has become a source of serious concern,” the report states. “The chain pays lip service to seafood sustainability in its corporate shareholder

reports, yet it continues to sell staggering amounts of products that are sourced from environmentally dubious fisheries and farms. Costco has no tangible sustainable seafood policy, participates in no significant initiatives, offers virtually zero transparency in its chain of custody, and has a large inventory of red list items. Compared to the other major players in the big box retail world, Costco trails far behind.”

Costco representatives admit they hadn’t responded to Greenpeace’s survey, however, they deny the claim they are doing nothing to support sustainable fish products. According to Costco’s Senior Vice President of Fresh Foods Jeff Lyons, each year the National Oceanic and Atmospheric Administration (NOAA) reports to the Federal Government on areas of fishing and species that it has found are being over fished.

“What we do on the fresh [foods] side is use that report to choose what to stock,” he said.

“We are also working with the World Wildlife Federation on their Salmon Dialogue,” Lyons continued. “They want to find the right science, and I think it’s creating real positives.”

Greenpeace also picketed the company headquarters on Tuesday, the day before the appearance of the blimp. Lyons said company representatives met with the activists and agreed to take their considerations under review, however, the two groups remained at odds over what the term “sustainability” means, and whether Costco had taken enough steps to address the issue of overfishing.