Even though we're carnivores, we have to say, we do occasionally feel some strong guilt about eating meat. Steak is delicious, but it comes at a pretty big environmental cost—raising cows and converting them into filets is energy and water intensive, much more so than vegetables. And if you're eating a crab cake in Baltimore, there's a good chance some of that crabmeat might have been flown in from as far away as Venezuela—that's a long, energy-wasting trip for a blue crab to take. But even when we start to feel the heavy environmental burden of our diet, we can at least feel OK when we suck down oysters. Oysters have huge environmental benefits—they filter gallons and gallons of water per day, making our bay healthier—and if the restaurant you're getting your oysters from recycles its shells, organizations such as the Chesapeake Bay Foundation can use those empty shells to grow new baby oysters, thus helping to replenish the depleted oyster population. Go to the Great Baltimore Oyster Festival, co-presented by Waterfront Partnership, the Chesapeake Bay Foundation, and Healthy Harbor, and enjoy some live music, view some Chesapeake Bay-themed displays, and eat a plate of oysters happily with the knowledge that you're helping out the bay. 1-5 p.m., West Shore Park, 501 Light St., (443) 743-3308, waterfrontpartnership.org, free to attend.