sciencehabit writes: The world banned most whaling in 1986, but sometimes it's hard to tell. The number of whales killed by whalers has doubled since the 1990s, with so-called scientific whaling claiming roughly 1000 annually, and perhaps 600 more captured by scofflaw nations. The International Whaling Commission (IWC) appears stuck on developing new conservation agreements. Now several researchers are proposing a possible solution: Create a cap-and-trade market for swapping permits to kill whales. But critics of the “whale shares” idea have already sharpened their harpoons.