December 4, 2002

FOR MOST OF us, I suspect, there is something deeply off-putting about being asked to think about the implications of what we eat. Many of us are already under some degree of pressure to reduce the fat, sugar, and salt in our diets. And as if that weren't bad enough, columns like this one from time to time sound increasingly dire warnings about the effects of human food production on the earth and its various inhabitants.

The warnings tend to be dire because the news tends to be bad, but it isn't all bad. Recently I was directed to the Web site of the Monterey Bay Aquarium (www.montereybayaquarium.org), whose main page includes a "Seafood Watch" link I was certain would be purest doom and gloom (none of this, never any of that) but turned out to be something more like a summer thunderhead, with some ominous dark blooms pierced by the occasional ray of brilliant sunlight.

It turns out that there are well-managed fisheries, many of them on the West Coast. My beloved Dungeness crab, for example, is a delicacy we can enjoy with a clear conscience; although the catch varies dramatically from year to year, a combination of regulations and harvesting techniques means that females, undersize crabs, and "bycatch" – marine life the crab fishers don't want – are easily returned to the sea. The result is a stable crab population and a sustainable yield of edible crab. Another flourishing species that's good to eat is halibut, which is fished in a way that produces very little bycatch.

Some of the usual no-no suspects turn up – Chilean sea bass, of course, and Atlantic swordfish – but there are a few surprises too, among them the bluefin tuna, a sushi favorite that's been badly overfished, and mahi-mahi, which appears to be abundant but "has never had a scientific stock assessment." Petrale sole, a local institution, is taken in a way that disturbs sandy seabeds, though those seabeds appear to be subject to natural disturbances, such as storms, anyway.

And while fish farming has taken a bit of a (justified) media hosing in the past few years, for wastefulness and ecological damage, some farmed fish are good choices for the conscientious. Among them: trout, an efficient carnivore; and striped bass, a tank-raised hybrid that does not pose a threat to natural bodies of water or their native wild species.

Perhaps the most complex case is shrimp. The imported varieties, whether farmed or wild-caught, are verboten. The domestic stuff is better: shrimp farms in the United States are subject to tight environmental regulation, and U.S. fishermen use techniques to minimize bycatch. Not sure? Ask before buying. And don't buy purely on price.