This article is part of a package on ethical seafood. For mouth-watering recipes, sustainable seafood news, and myriad resources to help readers stay informed and eat sustainably visit www.utne.com/Seafood.

The following seafood suggestions are adapted from the ultra-informative appendix to Bottomfeeder, in which Taras Grescoe shares his personal recommendations for sustainable fare. Grescoe's experience, drawn from "a decade of fish eating, and a year and a half of visiting markets and reading menus worldwide," is extremely helpful in explaining the sustainable way to enjoy those "sometimes" seafoods: the fickle favorites we can still enjoy eating, but under the proper circumstances.--The Editors

Absolutely, Always: Artic char, Halibut (Pacific), Herring, Jellyfish, Mackerel, Mullet, Mussels, Oysters, Pollock, Sablefish, Sardines, Squid, Trout 

No, Never: Bluefin tuna, Chilean sea bass, Cod (Atlantic), Dogfish, Flounder, Grouper, Halibut (Atlantic), Monkfish, Orange Roughy, Sharks, Skates, Sole (Atlantic), Tilefish

Sometimes, Depends…

Anchovy. Low in mercury, high in omega-3s. Available canned, salted, pickled in vinegar, and fermented in Asian sauces. Though flavorful and good for you, anchovy numbers in the North Atlantic and Mediterranean are at an all-time low. Until the fishery in the Bay of Biscay is reopened, avoid.

Cod, Pacific. An excellent alternative to Atlantic cod. Though there is some bycatch with trawl- caught Pacific cod, much is caught with bottom longlines, which have lower rates of bycatch.

Crab. Thanks to the disappearance of their main predators, crabs are doing quite well. King crab from Russia, much of which ends up in chain restaurants, is considered overfished.

Haddock. Bottom-longline and hook-and-line-caught haddock from the United States and Canada is a good choice (and an excellent alternative to cod in fish and chips). Much haddock, unfortunately, is still caught with trawls, with high bycatch levels.

Lobster. Sweet- fleshed Atlantic lobster is generally a good choice, though there is uncertainty about overfishing in the Gulf of Maine. Spiny or rock lobster from Central America, much of which ends up in chain restaurants, is overfished with substandard gear that kills and cripples divers.