Sheba, the Mars-owned cat food brand, will sell entrees made from only sustainably sourced seafood by the end of 2013, the company said Monday.

In 2010, Mars, the McLean, Va.-based food, candy and pet care company that also owns Wrigley, promised that all of its food would contain sustainably-sourced seafood by 2020. Mars pet food brands include Pedigree, Whiskas, Cesar, Royal Canin and Greenies. The Sheba announcement is the first milestone toward the 2020 goal, and pertains only to the U.S., the company said.

"We understand the importance of our ingredient-sourcing choices and how they can make a positive impact on the environment," Tina Garcia, marketing services director for Mars Petcare US said in a statement. "By using responsibly-sourced fish for our Sheba entrees, we have made it easy for pet owners to shop with confidence and to reward the most environmentally responsible fishing practices."

Mars will use the Monterey Bay Aquarium's Seafood Watch recommendations to determine the sustainability of various fish. The aquarium provides lists of fish by region, categorized by "best choices," like Dungeness stone crab in the Midwest, "good alternatives," like domestic Mahi Mahi and seafood to "avoid," like Atlantic salmon.

"We are pleased to see SHEBA taking a leadership role in protecting the world's oceans" Seafood Watch director Jennifer Dianto Kemmerly said in a statement. "By offering responsibly-sourced fish entrees, the brand is demonstrating a genuine commitment to supporting healthy and diverse ecosystems."

Mars follows major grocers like Walmart and fast food chains like McDonald's in a commitment to purchasing sustainable seafood.

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