A Plague of Rats and Rubbervines: The Growing Threat of Species Invasions. Yvonne Baskin. Island Press, Shearwater Books, Washington, DC, 2002. 330 pp., $25.00 (ISBN 1559638761 cloth).
A Plague of Rats and Rubbervines is a courageous and largely successful attempt to summarize the immense environmental and economic impacts of invasive alien species on a planetary scale. The scope of the book is staggering, encompassing viruses, grasses, insects, and pigs. Indeed, one of the few weaknesses of the book is its nearly overwhelming avalanche of examples. Although a more explicit map through the labyrinths of the subject might have been helpful, Baskin provides enough road signs and rest stops to make the journey compelling. Just when the reader risks losing track of where the story is going amid a staccato review of impending, ongoing, or historic disasters, Baskin imposes a bit of structure or a welcomed in-depth account to illustrate a central point.
In addition to presenting the problems created by moving organisms around the globe at an evolutionarily unprecedented pace, Baskin promises to offer solutions. And it is here that the book becomes a bit disappointing. To be fair, the difficulty is more scientific and institutional than literary, and one ought not to fault the messenger. Indeed, if the author is a tad optimistic, she is also scrupulously honest. In summarizing the state of knowledge, Baskin admits, “So far, then, we have neither a Holy Grail nor a set of powerful formulas for predicting invasion success.” In fact, we don't have much of a clue at all. This might be a bit harsh, but it seems that the best that ecologists have come up with is a theory of recidivism (past invaders are likely to be repeat offenders), a general rule that “more is worse” (the larger the founding population, the more likely it is to establish), and a self-evident notion of probability (the more often an organism arrives, the better its chances of succeeding).
If ecologists have only a vague sense of what is happening, policymakers and economists are in even worse shape. At several points, Baskin notes that society should shift the risk burden of invasive species to those who benefit from international trade and travel. This “polluter pays” principle seems reasonable, but we are left with a fuzzy notion that somewhere within the toolbox of civil fines, criminal penalties, special taxes, mandatory insurance, fees, and bonds must lie the means of constructing a coherent defense. The supposedly model systems of Australia and the Galapagos Islands appear to be marginally effective and enormously expensive. The analogy of “holding back the tide with a squeegee” seems disappointingly apt.
I read with particular interest the section on biological control, an area of my own professional interest. Baskin managed a remarkably evenhanded treatment of a polarized set of issues. She suggests that the field of biocontrol has cleaned up its act from the early days of introducing cane toads and mongooses, noting that “modern codes of conduct formalized in the 1990s direct researchers to seek out single-minded natural enemies that attack only the intended target.” But she admits, “The days of using vertebrates with broad appetites for biocontrol are not all behind us,” describing the recent release of exotic carp to control an outbreak of snail-borne parasites on catfish farms. Baskin goes on to point out that, “since the 1990s, ecologists have increasingly taken classical biocontrol to task for the real or potential damage that invertebrate agents have inflicted on native species.” She neatly puts both this contention and the “show me the damage” defense of the biocontrol community into perspective, noting that “despite the flurry of such reports, direct evidence on nontarget damage by biocontrol agents has been hard to come by, especially because there are not many people looking, certainly not the agencies that released the bugs in the first place.”
The book targets the general public, or at least the environmentally conscious segment of society. If the book is intended for a primarily US market, then the use of metric units is a mistake. Most people in the United States, can't picture a 6-meter-high wall of shrubby vines or convert 100 kilometers into miles. Telling people that a particular weed infests 5 million hectares is not very informative; few of my undergraduates know the approximate area encompassed by an acre, let alone a hectare. For that matter, big numbers become meaningless without a context. Baskin reports that foreign ballast water pours into our ports at a rate of 9 million liters per hour—most people don't know how much a liter is, and if they did, they almost surely couldn't comprehend the volume of 9 million of them. On the other hand, she does convert the 5.33 billion metric tons of seaborne trade in the world into a line of 18-wheelers circling the earth 60 times. That's a lot of stuff.
Baskin claims that her writing curbs the “lurid excesses” of popular accounts that refer to our warlike efforts to “battle noxious, exotic green cancers that establish beachheads and overrun natives.” Fortunately, she reneges on her promise—or at least she stretches its limits. Although she avoids melodramatic prose, she writes with conviction. Numbers don't motivate people, but the passion that infuses Baskin's descriptions of the effects of alien invasive species on native landscapes and people might. Occasionally her prose becomes a bit hyperbolic (e.g., “Today, Darwin would find all of the world's temperate grasslands…utterly transformed by invasive plants”) or even technically erroneous (e.g., including gypsy moths and scale insects in a list of “spineless predators”), but overall her passion arises from a solid, scientific understanding of the nature and severity of the issues.
My only substantive disappointment with the level of scholarly work in the book is Baskin's brief venture into environmental ethics, which concludes, “It would be hard to claim on purely philosophical grounds that a kokako is intrinsically better, more natural, or more valuable in New Zealand than a starling or a rat.” In fact, there is considerable ethical basis for claims of inherent value of native species. It is mistaken to cavalierly dismiss the field of environmental ethics, when such arguments underpin the social values and individual behaviors that Baskin hopes to change. But the damage to her case is not fatal: Whether or not introducing starlings and rats is “wrong” in a moral sense, such invasions are clearly economic, social, and cultural disasters.
I am not sure that the average reader will have the patience to wend his or her way through 330 pages of dreadful news, with only a glimmer of hope. Despite Baskin's attempt to foster optimism, the overall sense is—unfortunately but perhaps honestly—one of drowning in a rapidly rising tide of alien species. Stopping this species or eradicating that one seems to be an expensive and exhausting delay of the inevitable. If there is any cause for hope, it lies in the efforts of writers such as Baskin, who are willing to conduct extensive research and present information in a manner that is generally accessible to the public. Indeed, the most effective solution might be to quarantine the members of Congress (or whatever governmental body is appropriate) and release our leaders only after they've demonstrated that they've read and understood A Plague of Rats and Rubbervines.