Farm-raised salmon from Chile, top, shows the lighter color and more abundant fat characteristic of a farmed fish. The darker, leaner salmon at bottom was wild-caught in Alaska. (Deb Lindsey/For the Washington Post)

VERLASSO farmed salmon from Chile is available in a variety of markets. To find one, check “Where to Buy” at Many of the vendors listed are distributors; call the one in your area to find retail outlets. In the Washington area, Verlasso is distributed by Samuels & Son Seafood.

WHOLE FOODS MARKET says it is fully committed to sustainable seafood and buys only from farms that meet its detailed requirements, which specify salmon aquaculture policies on antibiotics, hormones, parasiticides, contaminant levels, environmental impact and many other factors.

COSTCO has worked with the World Wildlife Federation on sustainability issues since 2006 and is working with farmed salmon suppliers to implement standards set by the Aquaculture Stewardship Council.

TRADER JOE’S has a stated policy of “shifting to sustainable sources.” The company’s Web site says, “We are in the process of developing a set of standards” for its farmed-salmon suppliers.

GIANT has a Farmed Salmon Improvement Program. The company’s Web site says the supermarket chain “work[s] with the salmon farms that supply our stores to continually improve the sustainability of their product.”

— Tamar Haspel