Alaskan Pollock
If you've ever cooked frozen fish sticks, eaten surimi (imitation crab), or bought "fish" at McDonald's, you've probably eaten pollock. The Alaskan pollock fishery is the most productive seafood fishery in the world, catching two billion pounds of the fish each year. Thanks to good practices and the fish's rapid reproduction, it's also one of the world's healthiest fisheries. If there's drawback, however, it's that pollock nets sometimes incidentally catch king salmon, but Oceana is working with fishery managers to reduce wasted salmon bycatch.

Halibut
These flat fish have both eyes on one side of their bodies so they can lie concealed on the ocean floor. The Pacific halibut is caught mainly in Alaska and British Columbia with bottom longlines, gear that has generally benign impacts when used on the sandy seafloor preferred by halibut. But the fishery does have some bycatch problems as seabirds like the albatross can drown on the hooks. The California halibut is caught by bottom trawls, bottom longlines, and hook and lines. Of these, the hook-and-line fisheries have the least impact on the seafloor and the least bycatch. While the population of Alaskan halibut appears to be stable, the California halibut's status is unknown. Both types of halibut have become a popular substitute in menus for overfished species, but try and stick to Alaskan halibut or hook-and-line-caught California halibut.

Pacific Cod
Unlike its overfished Atlantic cousin, Pacific cod is still fairly abundant. This mild white fish can be prepared a number of ways, including battered and fried. As with any seafood, however, how it's caught is the name of the sustainability game. Cod caught with bottom trawls, which rake and destroy seafloor habitat, is less ecologically friendly than line-caught cod.

Alaskan Salmon
Salmon made big news earlier this year when the California and Oregon fisheries were shut down to fishermen in the largest closure ever on the West Coast. For reasons still unclear—likely a mix of overfishing and other ecological causes—salmon weren't returning to spawn in rivers in the massive numbers they had in years past. Fortunately for salmon lovers, Alaskan salmon still boasts some healthy populations. Ask for Alaskan, and ask for it wild—farmed salmon isn't nearly as environmentally friendly or as delicious.

King Crab
King crab may be most well-known these days thanks to Discovery Channel's Deadliest Catch, but it has been coveted as seafood for a long time. The name refers to several species, including golden, blue, and red king crab, but they're all large, asymmetrical crustaceans found in Alaska and the Pacific Northwest. This is a well-managed trap fishery, but buyer beware: According to the Monterey Bay Aquarium, Russian king crab is sometimes sold under a U.S. name, and these crabs come from an introduced, invasive species that has wreaked havoc on native Russian ecosystems.

Lingcod
Another bottom dweller, the lingcod is native to the West Coast. After overfishing threatened the lingcod population, catch restrictions allowed the population to grow again. It's still not fully recovered, however, and it's also caught using the dreaded bottom trawl, so stay away from lingcod for now.

Marlin
As one of the iconic sport fishing species, the marlin is best visualized arcing above the water on the end of a sportsman's line. It's unlikely to be found on menus as a commercial species, but it's still a favorite target= of recreational fishermen. Two species of marlin—the blue and the striped—have paid a high cost for their aesthetic appeal. Rampant overfishing has led to a dramatic decline in marlin populations in the Pacific and the Atlantic, and the marlin isn't alone in that regard. Scientists say that 90 percent of the big predator fish, such as sharks, swordfish, and tuna, have disappeared since 1950. These fish are particularly vulnerable to overfishing because they grow and reproduce slowly, and they provide bragging rights to fishermen who hook the big ones. Oceana is hard at work to reduce overfishing so that species like the marlin can flourish for generations to come.