Tribune staff report | Trader Joe’s has posted a notice on its Web site stating that it has introduced a goal of only purchasing seafood from sustainable sources by Dec. 31, 2012. “We are working with third-party, science-based organizations to establish definitions and parameters for this goal. It is our intent to have this goal function as a seafood policy that addresses customer concerns including the issues of over fishing, destructive catch or production methods, and the importance of marine reserves,” the statement reads.