Remember that helpful techie friend? Here's his marine equivalent, shrunk down to wallet and smart phone size. Known as "the fish cards," they are ready to help you choose healthy and ecological seafood customized for whatever part of the country you live in. They are well researched by experts and presented for you to choose from seafood that is "abundant, well-managed and caught or farmed in environmentally friendly ways."

Download the pocket guide from the Monterey Bay Aquarium at SeafoodWatch.org.

For example, say you live in the Northeast. Here's a trimmed-down version of that area's guide:

Green (Meaning: Go for it!)
Clams
Mussels
Oysters (farmed)
Crab: Dungeness, Stone
Halibut: Pacific+
Lobster: Spiny (US)
Salmon (Alaska wild)+
Scallops: Bay (farmed)
Trout: Rainbow (farmed)
Tuna: Albacore (troll/pole)

Yellow (Meaning: Not great, so try to minimize)
Black Sea Bass
Haddock (hook and line)
Lobster: American/Maine
Oysters (wild)
Scallops: Sea (wild)
Shrimp (U.S., Canada)
Swordfish (U.S.)*
Tuna: Bigeye, Yellowfin (troll/pole)

Red (Meaning: Avoid)
Chilean Sea Bass/Toothfish*
Cod: Atlantic
Crab: King (imported)
Haddock (trawled)
Salmon (farmed, including Atlantic)*
Sharks* and Skates
Shrimp (imported)
Snapper: Red

And to get even fussier, they provide a "Super Green" list as well. This list takes the larger list of sustainable seafood and picks the ones that are healthiest for you because they tend to contain the least environmental contaminants and the most omega 3s. That Northeasterner will find Super Green options like farmed mussels, oysters, rainbow trout and Coho salmon, as well as wild albacore tuna, Pacific sardines and Alaskan salmon.

See, it's just that easy.

Graham Hill, founder of TreeHugger.com, is currently crossing the Pacific on the Plastiki. Learn more at ThePlastiki.org and make a Plastiki pledge at MyPlastiki.com.

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