At the End of the Line

Many chefs serve farm-raised fish on the grounds that farming operations do not deplete wild fish stocks. Since the 2005 ban on U.S. imports of beluga caviar, Klink offers American farm-raised caviar instead. Barramundi, an Australian reef fish that is farm-raised in Massachusetts, appears regularly on the menu at Oceanaire.

Last month, Equinox downtown started serving ribs from pacu, a farm-raised Chilean fish with a diet of berries and nuts. The fish's ribs, which chef Todd Gray serves with a maple-balsamic glaze and fennel coleslaw, taste as smoky and tangy as meat ribs, but lighter.

Other farmed fish, however, have their own environmental downside. Farmed salmon remains popular with U.S. consumers because it's cheaper than wild, but scientists and environmental activists say the open-water fish farms that produce them can pollute the ocean while consuming vast amounts of smaller, wild fish as feed for the salmon.

"People generally assume whatever they're served in a restaurant is okay," said Michael Hirschfield, a senior scientist with the advocacy group Oceana. "This is dangerous when it comes to some popular farmed fish, like salmon, since they are raised in ways that cause tremendous problems in the ocean."

Attempts to buy only sustainable fish often put American chefs in the position of being international brokers, taking cellphone calls from island fishermen who relate what they've hauled up that same day. Because bluefin tuna -- a fatty, open-ocean fish popular with sushi purveyors -- is in trouble, Seaver buys blackfin tuna from a three-person fishing cooperative in Tobago. The fishermen call Seaver to tell him what they've caught; if he gives his okay, the fish arrives in Washington within 24 hours.

"These guys can't catch enough fish to make them go away," Seaver said. The Tobago fishermen spent a week showing his chef de cuisine, Joshua Wigham, how instead of using trawlers that often unintentionally kill hundreds of other fish, they bring in catches with an individual hook and line.

Some fish, no matter how similar the names, are not exact substitutes for each other: Blackfin tuna is leaner than bluefin, has a sweeter flavor and picks up smokiness from the grill. While chefs often compare one species to another -- Klink describes barramundi as "like a meaty striped bass" and sometimes pairs it with a meat sauce -- they also try to highlight the virtues of lesser-known fish such as mackerel.

"When a guest comes in and says, 'Can I have the Chilean sea bass?' it's our responsibility to say, 'No; this is why,' and offer a solution," Seaver said.

When it comes to finding sufficient supplies of sustainable fish, East Coast chefs sometimes have more difficulty than their West Coast counterparts. That's because fish stocks in Alaska are thriving, and some Western fisheries are doing better than ones in the East. Christopher Pauls, head chef of Mare restaurant in Boston, said that when he moved from San Francisco two years ago he found it harder to live up to his promise of an all-organic restaurant.

"Now I try to get whatever I can, where I can," Pauls said.

He and others consult the Monterey Bay Aquarium's Seafood Watch list, at http://www.seafoodwatch.org, outlining which stocks are depleted from overfishing or contaminated by pollution. A year and a half ago, the aquarium started advising 44 restaurants, nearly all of them on the West Coast. The aquarium has printed and distributed more than 22 million wallet-size guides based on the watch list, and it runs an annual conference. Hook includes a guide produced by the Blue Ocean Institute, with every customer's check.

Sheila Bowman, who runs the aquarium's Seafood Watch outreach program, said some restaurants realize their patrons are judging them on their corporate responsibility. "These are businesspeople," she said.

For many chefs, though, the commitment hasn't exactly resonated with diners.

"To tell you the truth, the customers would never know the difference," Pauls said of his seafood policy. "Sometimes people come in and ask us a question about it, which is really satisfying."

But many marine scientists and international officials say the efforts are changing public attitudes. "More and more people are pulling out those little guides," said Julia Marton-Lefèvre, director general of the World Conservation Union. "We've got to be patient."