McDonald's has strict sustainability standards for all its fish; according to McComb, the three characteristics of flavor profile, quality, and sustainability are always the most important factors when deciding to purchase a type of fish, and they even trump price; so the decline in purchasing doesn't necessarily mean the company doubts its sustainability. At Yum! Brands' (YUM) Long John Silvers, hoki has been taken off the menu -- but a spokesperson didn't say why (though the company has previously described its purchase of New Zealand hoki in glowing terms).

So should McDonald's use hoki -- and should any restaurant or frozen food manufacturer buy the fish? The tone of the New York Times piece seems to suggest that hoki, especially that caught off the shores of New Zealand, is a less sustainable choice. Certainly, the World Wildlife Fund agrees. Australia WWF fisheries program manager Peter Trott told the New York Times that ecosystem damage, population declines, and the accidental killing of other marine creatures -- skates, sharks and seals -- is untenable. "We have major concerns" about the sustainability of New Zealand hoki fishing.

Despite his concerns and the falling fish stocks, the Marine Stewardship Council renewed its sustainability certification for New Zealand hoki in 2007 (certifications last five years). New Zealand has responded, fearful of repeating the disastrous fate of the orange roughy (which once made up a large proportion of commercial white fish), reducing the annual quota from 275,000 metric tons in 1996 to about 100,000 today. In other areas of the world, especially Chile and Argentina, hoki quotas are declining too; in the first half of 2009, the Argentinian hoki catch was down 26 percent (about 25,000 metrics tons in the first four months of the year).

And of the 100,000 tons of hoki caught in New Zealand, only 29 percent is exported, much of it to China, where it's processed into fish sticks and fish filets for us to eat in the U.S. and Western Europe. In all probability, this fish is combined with hoki and hake from Argentina and Chile, and cod and pollack from Alaska, not to mention the Patagonian toothfish, another species for which international quotas are being set.

The facts are confusing and often disputed, and the truth is that no one fish can be seen as a sustainability darling. Because if it is? It's surely bound toward overuse. The international fishery industry operates in a constant state of balance and rebalance, with a vast number of governmental agencies, environmental watchdogs, wildlife groups, consumer advocates, and corporate interests pushing and pulling to find the right way to harvest natural resources without destroying them altogether; all in the face of rising ocean temperatures that are throwing the whole delicate structure into chaos.

It's a house of cards, and just as there is no one perfect fish there is no one perfect corporate consumer. McDonald's and Yum! Brands could be seen as equally culpable; or equally admirable, depending on the fish we're focusing in on today. The hoki might be ugly, but it's this week's fashion plate. Whether it will be next week's, or next year's, very much depends on factors entirely beyond all of our control.

Should hoki be used in Filet-o-Fish sandwiches? Yes. And no. And I don't know? McDonald's sustainability objectives look as admirable as they can be, given the circumstances. For once, I have to applaud the fast food company on its initiatives.

Even though my answer to the headline question is still, "I don't know."