Life
out of Bounds: Bioinvasion in a Borderless World.
1998. Chris Bright. W.W. Norton, New
York. 287 pp. Paper.
In
1930, embedded in the cargo of a New York-bound ship bringing
elm logs from Europe were two additional imports: the fungus
that causes Dutch elm disease and the beetle that helps spread
it. This disease would kill millions of American elms over
the next 70 years, leaving streets and parks across North
America stripped naked. The story of this "biological
invasion" is one of many that Worldwatch Institute's
Chris Bright uses to illustrate the harmful effects of globalization.
For as long as people have crossed the oceans, plants and animals have tagged along with them in shipping containers, ballast tanks, and, more recently, in commercial airliners. Only a fraction of these organisms are able to survive the journey and, among those, only a few can establish themselves in their new location. But, despite a low survival rate, the damage these bio-invaders can do to infrastructure, public health, and other organisms in their new homes is extensive.
With no natural threats from predators or disease, these invaders can easily multiply and drive other plants and animals to extinction. When they're not nudging others onto threatened or endangered species lists, these aliens can spread disease--both human and animal. They can also displace thousands of people as happened when a water hyacinth introduced to Africa’s Lake Victoria dramatically reduced oxygen and light levels. Fish numbers soon declined, leaving fishing families without a livelihood and forcing many of them to move into cities.
Add to that an increasing pesticide dependence, a reduction in the supply of fresh water (some plants drink more than their new habitats can accommodate), and a host of other ills, and the increasing movement of these creatures becomes as Bright puts it, "another way of measuring the unsustainability of the contemporary economic order."
Bright explains the various ecological reactions to alien species clearly and with simple language, making this book a good primer on ecology for the non-scientist. The chapter on islands is itself an excellent introduction to biogeography. The author not only simplifies science but relates it in an interesting way to history, commerce, and several other subjects as well.
Bright studied literature in college and was a writer for popular magazines before joining Worldwatch. His love of language is apparent in his use of some unique terms to describe environmental hazards. Among them: "ecological narcotics" (pesticides and herbicides), "biological vandalism" (introduction of species for hunting and fishing), and "genetic pollution" (crossbreeding of exotic and native species). He uses the term "weed" to refer to any foreign invader, plant or animal, that is highly prolific, adaptable, and menacing. While these terms might be familiar to the environmentally hip, some of them will no doubt begin appearing in the layman's vocabulary as well.
The narrative of unintended consequences of some intentional plant and animal introductions shows how even the environmentally aware can see their efforts backfire. A freshwater shrimp introduced to streams in the western U.S. as a potential feed for salmon some years ago ended up eating the plankton immature salmon depend on. This tiny shrimp all but exterminated the salmon and with them the local bears and birds of prey that had depended on the salmon for food. Brief stories like this one fill most of the book and take the reader on a biological journey to all continents and a variety of ecosystems.
Bright describes some of the introductions by European explorers and colonists as a harmful by-product of Europe's domination of the lands and people of the tropical world. His description of this period of early biological movement and the reasons behind many of the releases is intriguing. Among the historical accidents he details:
European maritime explorers routinely dropped off small herds of pigs on uninhabited islands so that they could count on stopping there on future travels for fresh meat. Unfortunately, these barnyard animals tend to eat just about anything and in the absence of predators, their numbers flourished while native flora and fauna were all but wiped out.
In the 1860s, a French artist and entomologist hoping to establish a silk business brought the gypsy moth to his home in Medford, Massachusetts. Eventually the enterprise failed, some moths escaped, and deciduous trees of eastern North America have been periodically devoured ever since.
Sailors stopping in Hawaii in the early 19th century emptied their mosquito-infested water containers in order to fill them with fresh water. Before that time Hawaii was not home to any mosquitoes. Now, these insects are hosts to two viruses that are deadly to birds in Hawaii.
Bright's final section, titled "Remedies," has only one chapter: "Toward an Ecologically Literate Society." Much of this chapter describes current efforts (and some of their flaws) to curb alien introductions. Over the years, governments and other policy makers have tried counter-introductions of viruses, parasites, and predators, along with pesticides, herbicides, and international shipping agreements, in their efforts to combat the spread of damaging organisms. This chapter argues that raising public consciousness about the problem is essential to solving it. Some readers may feel that they can do little to reverse the global invasion Bright so lucidly describes. But becoming aware of the ecological effects of the transport of plants and animals is a good first step in the battle and this book is an easy and interesting way to start.
Alvin Hutchinson is librarian at the Smithsonian National Zoo.
ZooGoer 28(3) 1999. Copyright 1999 Friends of the National Zoo. All rights reserved.
