What's Behind the Honeybee Decline? Perhaps Not What You've Heard

Rachel Carson‘s Silent Spring is widely recognized as the founding document of the environmentalist movement. Less widely recognized, but equally important, is why. For 40 years before the book was published in 1962, scientists concerned about toxic contamination had been trying to draw a solid link between pesticides and public health. The link eluded them. What these scientists were routinely unable to do-either for lack of evidence or literary eloquence-Carson eventually did. Meticulously, and with narrative grace, she connected the dots between pesticides and a host of health problems (bearing on all forms of life), thereby sparking an intense political response that continues to this day.

The environmental movement thus began with a bang: a general environmental problem (toxicity) was shown to have a specific and readily verifiable environmental cause (certain pesticides) that stood head and shoulders above other possible explanations. To be sure, there was controversy-most notably on the issue of DDT and malaria-but the court of public opinion was generally convinced that Carson, who died of cancer in 1964, had made her case against organophosphate and chlorinated hydrocarbon pesticides.

Carson’s accomplishment, for all its impact, bequeathed to the environmentalist movement a daunting legacy. The ecological ills that Carson identified became a poignant cautionary tale for an agricultural system hooked on chemicals. As such, an unintended consequence of Silent Spring was to encourage the emerging environmentalist movement to rely heavily on the power of relatively simple cautionary tales to engage grassroots action.? Ever since Carson, when an environmental problem has been identified, no matter how complex the underlying ecological factors, it’s often packaged as a morality lesson highlighting the impact of a single, human-driven environmental sin.

But this standard approach to environmental problems, while translating seamlessly into short press releases, can backfire in ways that gradually weaken the movement. Ultimately, it ignores the central point that ecology is as messy as it is beautiful, and that establishing bull’s eye causation is often like throwing a dart into a cyclone.

The allure of singular causation is hard to resist. When, in 1987, a barge from New York holding 3,000 tons of trash floated up and down the East Coast without finding a landfill able to take the garbage, environmentalists deemed it a cautionary tale about the nation’s maxed-out landfills.? When, in 2000, the first weeds resistant to genetically engineered (herbicide-resistant) crops appeared, environmentalists turned it into a cautionary tale about the decline in diversity of cultivated plant breeds. And when, most recently, H1N1 swept the globe, environmentalists rushed to tell a cautionary tale about the inherent dangers of factory farms. Such reductions to a single cause are satisfying. They stoke a sense of outrage and inspire a quest for justice. They also make it clear who is at fault.

But in each of the above cases, the cautionary tale never quite captured the deeper causes. Future assessments showed landfill space to be far from a premium; a recent report from the Dutch Center for Genetic Resources has revealed that seed biodiversity has actually increased since the advent of GE seeds; and the H1N1 virus’s origin has yet to be positively linked to factory farming. In fact, the USDA goes so far as to note that free-range swine, by virtue of being outdoors and exposed to wildlife, are more susceptible to certain pathogens than confined pigs.

These misfires matter. Every time a cautionary tale fails to demonstrably confirm the identified cause, the environmental movement comes off as rashly leaping before looking, placing politics ahead of science.

And now it appears another cautionary tale may be veering off its mark. It involves the rapid decline of honeybees in the United States-a depressing phenomenon called “colony collapse disorder.” Since 2006, when American farmers and beekeepers began to lament drastic declines in hive populations, environmentalists have been packaging CCD as a cautionary tale confirming our excessive reliance on-once again-harmful pesticides.

As it became clear that this decline was indeed real (40-50 percent in the US since 2004), environmental interests began to construct the narrative. Democratic Underground explained, “Imidacloprid Pesticide Most Likely Cause of Honeybee Colony Collapse Disorder.” Grist helped out: “So there’s this insecticide called clothianidin that seems likely to be implicated in colony collapse disorder,” offering as evidence the claim that “over in Germany the introduction of clothianidin coincided with a sudden bee die-off.” Environment 360 led with the headline “Behind Mass Die-Offs, Pesticides Lurk as Culprit.” And Mother Earth News joined the chorus, adding, “Colony Collapse: Are Potent Pesticides Killing Honeybees?”? As recently as March 2010, media reports have continued to stress the pesticide connection as the leading causative factor behind the nation’s declining bee population.

To date, no scientific evidence directly supporting this conclusion has emerged. Of course, this could change. The problem here is not that pesticides are a suggested cause of CCD-this seems perfectly reasonable to assume. Rather, it’s that they have been routinely favored-and sometimes politicized-as the singular or most likely cause when, as it turns out, there are a number of supplementary explanations that bear on the phenomenon. These explanations are neither as simple nor as damning of our behavior as the pesticide explanation. A January 2010 congressional report on CCD shows why.

Particularly compelling is the impact of the Israeli Acute Paralysis Virus (IAPV), which scientists have known about since the 1970s. This virus, which is transmitted by a Varooa mite, was identified by the USDA in 2007 as “a marker of CCD.” Although the USDA did not go so far as to call IAPV the cause of CCD, the congressional report did note that “research indicates there is a strong correlation of the appearance of IAPV and CCD together.” The report also stresses the likelihood of a pathogen-perhaps the fungus Nosema ceranae-being a contributing factor, “given that some bee colonies have recovered once their bee boxes were irradiated.” It briefly mentions a range of other factors, including the impact of feed supplements made with GE crops, changes in nectar flow as a result of climate change, and the growing gossamer of phone transmission lines, but adds, “these possible factors have not been substantiated by evidence examined by the key researchers of this issue.”

The report had something to say about pesticides as well. As environmentalists rightly-if too exclusively-pointed out, the new class of insecticide known as neonicotinoids was indeed being taken up by bees, along with a variety of fungicides and herbicides. Although not absorbed in lethal doses, these agents did raise concerns about “possible chronic problems caused by long-term exposure.” The report also recognized that the Organic Consumers Association claimed that collapses were not happening on organic bee operations. But it went on to mention that “there is conflicting information about the effect of these pesticides on honey bees,” adding that these chemicals had been discontinued in Europe while colony losses continued unabated. In the end, the congressional report placed the pesticide possibility in a broader and more complicated context, one rarely provided by anti-pesticide advocates, and one that makes the standard cautionary tale about pesticides leading to CCD that much harder to accept.

Media reports are beginning to catch on. In The Economist, a British apiary professor, speaking on the cause of CCD, was recently quoted as saying, “People want it to be genetically modified crops, pollution, mobile phone masts and pesticides.” But, he added, it’s “almost certainly none of these.” The BBC reported that CCD is actually a cyclical event rather than an anomalous tragedy. An Australian entomologist quoted in the article explained, “Researchers around the world are running around trying to find a cause of the disorder-and there’s absolutely no proof that there’s a disorder there.”

Perhaps most compellingly, an article in the recent issue of Conservation reports that, while indeed bee populations have declined in the U.S. since 2004, the global population of managed bees has, since the 1960s, risen by 50 percent while honey production has gone up 100 percent.? “U.S. bee losses,” writes Nathanael Johnson, “have been dwarfed by increases in places such as China, Argentina, and Turkey-countries which now dominate the honey supply.” Additionally, “the production of pollinator-dependent crops has quadrupled.”

None of this additional information has kept the keepers of the cautionary tale from capitalizing on the possible pesticide connection. For example, several environmental groups are bringing charges against Bayer CropScience to prevent the sale of two pesticides-popularly known as Movento and Ultor-on the grounds that they harm honeybees. Perhaps these agents should be kept off the market. I honestly don’t know. But I do know that if the means and ends are not consistent-that is, if dubious pretenses are deployed to promote positive environmental outcomes-a short-term victory will come at the expense of the environmental movement’s long-term viability. Carson, for her part, would have surely persevered to find the truth, ensuring that the changes she initiated derived from science more than suggestion.