Following the catastrophic earthquake and tsunami in Japan on March 11 and the ensuing events at the Fukushima Daiichi nuclear plant, the number of people who have asked me about seafood is more than I can count on all my fingers and toes. "Are you worried about fish?" they all want to know.

The short answer is, "sort of."

Although fishing has been suspended in Japan's northeastern waters, many Japanese citizens have given up eating seafood for the time being. Japanese officials have cited "radiation dilution" as the reason Americans shouldn't worry about the contamination of seafood. Still, the U.S. Food and Drug Administration has restricted the importation of certain foods from Japan (Japan contributes only about 4 percent of our food imports). And with the help of customs officials, the U.S. is screening food for traces of radiation. Japan was already on my naughty list, though, since they buy some 80 percent of the annual catch of Atlantic bluefin tuna — a fish known to be in danger of extinction.

Before March, however, I was already worried about fish. Last summer, Paul Greenberg stunned me when he reported in The New York Times that "Global seafood consumption has increased consistently to the point where we now remove more wild fish and shellfish from the oceans every year than the weight of the human population of China." This eye-opening data and more appears in his book Four Fish: The Future of the Last Wild Food, which should be required reading for anyone who catches fish or eats them. Ironically, it was published on the very day that a cap temporarily sealed the now-infamous Deepwater Horizon oil well, which for months had been spewing crude into the Gulf of Mexico.

Within two weeks of the explosion of the Deepwater Horizon, the National Oceanic and Atmospheric Administration had declared commercial fishing waters along the Gulf Coast contaminated and closed the area to fishing. Nearly half of respondents in one survey said they would only eat seafood if they knew it hadn't come from the gulf.

Since April of last year, NOAA and the FDA have been testing seafood sourced from the gulf. They recently declared it both free from petroleum and dispersants and safe to eat. Nevertheless, plenty of people are cautious about eating fish, and the nuclear scare in Japan has only strengthened their resolve. A few avowed omnivore friends of mine have now sworn off fish completely. "With gallons of nuclear waste dumped into the ocean, plus the oil spill," one of them told me recently, "it will still feel like poison to me, no matter what the FDA says."

A couple of Saturday nights ago, I had dinner with extended family at Pappadeaux Seafood Kitchen in Albuquerque. Given the throngs packing the cavernous dining rooms (and waiting an hour or longer for a table), you'd never know anyone was concerned about seafood safety, let alone sustainability. Curious about the sources of the restaurant's seafood, I spoke with a kitchen manager, who said they get all of their seafood from Houston, though he didn't know the names of specific fisheries. He added that, "When we run out, we do order locally, from Seattle Fish," a certified Marine Stewardship Council supplier committed to environmental and sustainability issues. That made me feel a little better — but not much.

Part of the reason I felt so disheartened was that I'd just picked up World Without Fish, the new book from award-winning author Mark Kurlansky. This colorful volume (with cool illustrations by artist Frank Stockton) outlines the decline of fish populations around the world as a result of overfishing, industrial pollution and climate change. It's full of both alarming statistics ("Most of the fish we commonly eat ... could be gone in the next fifty years") and reassuring steps you can take to help turn things around. It's is an educational read, whether you're 9 or 39.

"You could refuse to eat fish," admits Kurlansky, "but this would not only deprive you of a very healthy food, it would not help. If you refuse to eat any fish, then there is no reward for those who fish in sustainable ways. Instead, you should eat fish, but only good fish, fish that were caught in sustainable fishing." Kurlansky then suggests ways to identify "good" seafood — "beware of fish that is very inexpensive" and "beware of new types of fish" — and provides lists of organizations that offer guidelines (including California's Monterey Bay Aquarium, which publishes the popular "Seafood Watch" list).

It all comes down to asking questions and making the right choices. Sure, at the end of a long, hard day, I don't really want to play detective when I'm deciding what's for dinner. Kurlansky himself admits that eating responsibly is a "difficult task," but it's "one that we have a moral obligation to try to undertake." Whether there's been an industrial disaster in the news lately or not, when we're shopping or perusing a menu, we should all keep these words in mind.