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 or conserve whales. But critics of the “whale shares” idea have already sharpened their harpoons.
In an article  in Ecological Applications, Leah Gerber of Arizona State University (ASU), Tempe, and colleagues spell out how this controversial idea would benefit both whales and whalers. They argue it also could be a model for helping turtles, sharks, and seabirds. "The paper succeeds in shifting the dialogue about whaling, and actually modeling the crucial dynamic between whaling and conservation," says Stephen Palumbi of Stanford University in Palo Alto, California.
Setting up a system of controlled fishing permits—known as catch shares—has helped protect fisheries. And a cap-and-trade system for trading pollution permits was a clear success in controlling acid rain. Gerber, along with Chris Costello and Steven Gaines of the University of California, Santa Barbara, first proposed applying similar market-based ideas  to whaling in January 2012. In principle, they argued, a central authority could set a maximum harvest level, then offer shares or permits to anyone who wanted to buy the right to kill—including environmental groups that would have no intention of using the permit. The idea is that whalers might make more money by selling their permits to environmentalists than by actually killing the whales.
Now the trio has created a model to examine in more detail how a cap-and-trade market might impact whale populations and how the costs and benefits would change for people who want to hunt or conserve them. The model combines whale population dynamics with an economic model of demand for whales and shows what happens to prices and populations when whalers and nongovernmental organizations (NGOs) exchange shares. They examined the dynamics for three kinds of whales: minkes, bowheads, and gray whales.
North Atlantic minke whales number about 72,000, and 550 are caught annually, including for subsistence, as well as for scientific whaling. The model predicts that conservationists wouldn’t have any incentive to buy shares of minke whales until hunters deplete the population to a level of concern, which could take 10 years. But with bowheads, which are slowly recovering from intense whaling in the 19th century, conservations groups would be highly motivated to buy all the shares for 13 years, until the population grows to the carrying capacity. And they would purchase shares in gray whales for 30 years. With all three species, prices converged on $10,000 a share.
The total cost to buy all the whale shares of all three species over 20 years would run about $114 million, the researchers calculate. Considered on an annual basis, that’s a fraction of what NGOs spend now on whale campaigns. So, even at that price, conservationists could save more whales for less money than they do now, the authors conclude. And whalers would benefit when they sell shares because they make money without having to get their feet wet. “[A] well-designed whale conservation market simultaneously enhances conservation welfare and whaler welfare relative to the status quo," Gerber and colleagues write. "In some sense this is unsurprising: Allowing voluntary trade, rather than forbidding it, tends to make both parties in an economic transaction better off.”
Palumbi, however, says he doesn't put too much stock in these numbers. "The paper is almost certainly wrong in detail about whales and whaling," he says. "It misses many of the messy realities of modern whaling, such as the huge subsidy that Japan gives its whalers." The main advance, he says, is creating a framework for calculating the values of competing uses.
A companion paper , by Martin Smith, an economist at Duke University in Durham, North Carolina, and others, identifies several other problems with the idea. Any of these could lead to “lower overall welfare for society” and could increase threats to marine mammals, they say.
The first problem is known as free riding. A dead whale is, in economic terms, a private good. Only the ship that pays for the right to catch a whale will profit from it. But a living whale is a public good. If one NGO pays to keep it alive, all the other NGOs derive the same benefit. As do all the whale-lovers who never contribute to an NGO. That means it could become difficult for NGOs to raise funds.
Second, if trade in whale meat is legalized, it could be difficult to identify black market meat. Monitoring and enforcement would be a challenge. "These problems are not easily solved," adds Scott Baker of Oregon State University, Corvallis. His molecular sleuthing of whalemeat markets has shows a large trade in illegal or unreported whale products. A return to commercial whaling, he suspects, would provide even greater incentives for illegal hunting.
And then there is the hot-button issue of setting a cap and allocating shares. Politics is already a challenge at the IWC, where small nations sometimes trade votes for economic benefit. "Replacing the IWC’s fragile moratorium with cap-and-trade does not guarantee that the geopolitical entanglements that have generated the current stalemate will be eliminated," Smith writes. Worse, it could set off a dash to secure whaling rights in order to sell them later for cash.
Gerber and her colleagues concede many of these points, but say they are not unique to a conservation market.
Finally, what about the, well, moral repugnancy that some wildlife advocates feel about putting a price on majestic animals like whales? Gerber tried to address the issue last spring  in Issues in Science and Technology. "The debate in biodiversity conservation between economics and ethics, or between pragmatism and principle, is in many ways a misguided contest, one that assumes that there exists a deep philosophical division between environmental ethics and societal action," she wrote with her ASU colleague Ben Minteer, an environmental ethicist. "Being pragmatic in whale conservation policy does not mean selling out on conservationist principles."
At the moment, a whale market exists only in the realm of ideas. "My guess is that it would probably require a renegotiation of the International Convention for the Regulation of Whaling to make the structural changes required for the global whale auction envisaged," Baker says. For the foreseeable future, the battle over whales will continue to play out with unregulated hunts, dangerous zodiac chases , and freezers full of aging whale meat .