Your Chilean Sea Bass dinner deprives killer whales

By Brandon Keim Email Author
March 11, 2010 A one-of-a-kind killer whale population appears to be threatened by human appetites for Antarctic toothfish, better known to restaurant-goers as Chilean Sea Bass. As fishing fleets patrol their waters, catching what was their primary source of food, the whales are vanishing. It’s not certain whether they’ve only moved on, or are dying out, or both. But something is happening, with potentially dark implications for Earth’s last pristine ecosystem. “There’s been a dramatic disappearance of the whales,” said biologist David Ainley of ecological consulting firm H.T. Harvey and Associates, and co-author of a March Aquatic Mammals article on the whales’ disappearance. “We think they’re having a harder time trying to find food. Whether that leads to population decrease, hopefully we won’t find out. But we will find out, if it continues.” Antarctic killer whales form two types of populations, known to researchers as ecotype-B and ecotype-C. While the former resemble killer whales found elsewhere, ecotype-C whales are much smaller, with different markings and a tendency to gather in especially large groups. Many researchers now consider them a distinct species. Dubbed Ross Sea killer whales, ecotype-C whales are found only in the Ross Sea, an expanse of water off Antarctica’s southern coast, flanking the France-sized Ross Ice Shelf. Many scientists consider the region to be the last pristine ecosystem on Earth, the only remaining piece of pre-industrial nature. The Ross Sea, however, isn’t what it used to be. About 25 years ago, North American diners discovered the Chilean Sea Bass, the market-friendly name of the Patagonian toothfish. It is a large, codlike Southern Ocean fish that lives for a half century, breeds infrequently and is both tasty and easy to cook, and its populations were soon devastated. Fishing fleets moved into the Ross Sea, searching for its close relative, the Antarctic toothfish. Antarctic toothfish are now called Chilean Sea Bass, too. They’re thought to be the primary food of Ross Sea killer whales, which were described as common by the first Antarctic explorers and subsequent visitors. Just a few years ago, boats headed into the McMurdo research station on Ross Island were “literally surrounded by killer whales out toward the horizon,” write the Aquatic Mammal researchers. Not any more. Though ecotype-B whale sightings have remained steady, Ross Sea killer whale sightings are down by two-thirds in the last five years, and big groups no longer gather. …

Your Chilean Sea Bass Dinner Deprives Killer Whales