The vast majority of the world’s internationally traded seafood moves by sea. Many unfortunate fish find themselves ripped out of the ocean only to be gutted, frozen, shoveled into containers, and sent plowing across the top of it in a massive cargo vessel. The companies that transport seafood from port to port play an indescribably important role in the seafood industry’s chain of custody.; After all, if you can’t get a fish onto the land, it becomes a lot tougher to put it in the oven.

It is in this respect that the imperiled Chilean sea bass — or more appropriately, the Antarctic and Patagonian toothfish — have recently gained an enormous ally.

Maersk is the world’s largest shipping company. In addition to jet engine parts, hybrid cars, stretch pants, and countless other items, the Maersk shipping fleet transports approximately 20% of the world’s entire ocean-going seafood supply. It’s a staggering amount of frozen fish, and that’s why it’s so heartening to hear that the company is now refusing to ship any Antarctic or Patagonian toothfish due to environmental concerns.

How great is that?

David Pawlan, Maersk’s Line Head of Global Seafood, makes no equivocation about the reasons behind this progressive policy shift. “We recognize the global concerns over the overfishing of toothfish species,” says Pawlan, “and support efforts to curb this trade.”

Pawlan is right to be cautious in this regard. It has beyond debate that much of the toothfish industry is inextricably linked to a massive illegal fishing enterprise operating in an unregulated manner in the Southern Ocean. The tremendous market value of Chilean sea bass fillets has prompted the fishing industry’s equivalent of a Klondike gold rush in the Southern Ocean: a desperate, greed-fueled free-for-all in a frigid and lawless wilderness.

Maersk is a welcome addition to a small but growing movement to protect the toothfish. Greenpeace has been pressuring companies throughout the seafood chain of custody to stand up for this animal and its vulnerable habitat for years, but it hasn’t been until relatively recently that major players in the seafood industry have started to get on board.  In the United States, the world’s largest market for toothfish, some large retailers are beginning to take a progressive stance on this critical issue.  Ahold USA refuses to sell any toothfish products and actively disseminates information about the animal to its customers.  Wegmans, a smaller high-end grocery chain, has pledged not to sell any seafood from the Ross Sea — ground zero for Antarctic toothfish fishing – whatsoever.  Several other major US retailers have also discontinued their toothfish sales in the past year or two.

So the toothfish tide may be turning — but that’s not the end of Maersk’s commitment. The shipping company has also pledged that it will not carry any shark products, any whale meat or whale blubber, or any orange roughy, a fish notorious for its exemplification of unsustainability.

This is earth-shattering. We finally have a shipping company that is beginning to stand up for the very thing that keeps it relevant and in business: the ocean. Still, there are still some missing pieces, including a very important one: the last few members of the world’s most endangered commercial fish species still ride atop the waves in freezer containers stacked high on the deck of Maersk, Hanjin, and other shipping vessels — not to mention in the guts of trans-Pacific jumbo jets — and this animal has very little time left indeed.

We must stop trading in bluefin tuna. If not, we will lose it forever.