Who knew? Chilean sea bass is not from Chile, nor is it a bass. Since 1996, fishing vessels from a dozen nations have traversed the world’s most remote sea to catch the Antarctic toothfish.

The fishery lands 3,000 tons annually, selling much of it as “Chilean sea bass,” deceiving customers of high-end restaurants and supermarket chains around the world and threatening “the most pristine marine ecosystem on Earth,” according to the filmmakers behind “The Last Ocean,” which was recently screened at the Casino Theater.