Fringe attacks on invasion biology are completely without merit. The idea that a negative attitude toward invasive species is founded in, or a kin to, xenophobia or Nazi attitudes is ridiculous. It's historic precursor-hunting, not a swig of history. But equally troubling are statements of "benefits" to biodiversity. Perhaps this stems from the wrong-headed view that the goal of ecology, or management, is always to maximize biodiversity. The fact is that ecosystems can be radically altered by species introductions. The fact is that such alterations include wholesale shifts in communities, even when native species are not completely extirpated, including homogenization where communities become similarly populated when they once were completely different. This is occurring on an unnatural spatial and temporal scale due to man's actions. Zebra mussels are in continental Europe because of canals, in North America because of international cargo shipping, and bird migration could never have done that. It's bad because such introductions have hugely harmful effects. True, some effects of some exotic species can be counting as benefits, e.g. if you like clearer water then dreissenids have done you a service. But at what price? Biofouling and costly mitigation, extirpation of local fauna, and possible ties to harmful algal blooms and benthic community changes that result in collapsing fish populations. So even if you do not value native ecosystems at all, invasive species can be a huge drain on local and national economies. And if you are in the business of exploiting the environment (e.g. fishing, logging, providing recreational activities to tourists), you want sustainability. The last thing you want is to upset the status quo, let alone obliterate it, as species introductions can do. Not to mention nuisance effects such as wild population swings resulting in fish kills washing onshore, catastrophic tree death resulting in increased fire risk, and new vectors delivering new new human and animal pathogens.
Further, the notion that all sides of an argument should be presented equally in class is a disservice to students, because it elevates weak and invalid arguments to equal status with well-supported conclusions. After all, we do not teach that the earth may be flat or hollow, that air, fire, and water may be elements, or that evil spirits may cause disease simply because someone somewhere has believed it. Oh, and the fringe on this subject is far from objective, having began with commercial horticulture combating the idea that perhaps exotic ornamentals should not be planted for risk of harmful invasions. Check out: Simberloff, D., 2003, "Confonting introduced species: a form of xenphobia?", Biological Invasions, 5:179-192. Sincerely, Dave Raikow _________________________________________ David F. Raikow, Ph. D Research Aquatic Ecologist U.S. Environmental Protection Agency (EPA) National Exposure Research Laboratory (NERL) 26 W. Martin Luther King Dr. Cincinnati, OH, 45268 513-569-7383 (Office) 513-569-7609 (Fax) 513-646-1759 (Cell) [EMAIL PROTECTED] http://www.linkedin.com/in/davidraikow _________________________________________ Kelly Stettner <[EMAIL PROTECTED]> Sent by: "Ecological Society of America: grants, jobs, news" <ECOLOG-L@LISTSERV.UMD.EDU> 10/02/2008 10:12 AM Please respond to [EMAIL PROTECTED] To ECOLOG-L@LISTSERV.UMD.EDU cc Subject Re: [ECOLOG-L] Invasion biology reading "Date: Wed, 1 Oct 2008 11:49:36 -0400 From: "Peter W. Houlihan" <[EMAIL PROTECTED]> Subject: Re: Summary: Undergrad Class in Biodiversity I do not recommend using: "Theodoropoulos, David I. Invasion Biology: Critique of a Pseudoscience". It does not provide an unbiased view of the field and reads like a polemic." Actually, my own reading of Theodoropoulos' book was that he was "attacking" the polemic views that refuse to see "invasions" as anything other than evil. In point of fact, the Nazis did extirpate all non-native organisms from their Fatherland, from plant to human. Theodoropoulos makes sound arguments, and I have heard from other authors that introduced species do largely and ultimately benefit biodiversity. The number of species that become "invasive" after introduction to a "new" range is a mere fraction of the total number of introduced species. Also, why is it "bad" if a human introduces a species to a new habitat, but it's just fine when, for instance, flocks of migratory geese bring microscopic zebra mussels to a new waterbody? This is the "emotionalism" that Theodoropoulos is arguing against. I disagree with Mr. Houlihan; "Critique" would be a valuable source of discussion for your class. Science is about objectivity (as much as we can manage, since we are always, inevitably, part of our own observations and biases), so take every book you read with a grain of salt and a heavy swig of history. Kelly Stettner Black River Action Team (BRAT) 45 Coolidge Road Springfield, VT 05156 [EMAIL PROTECTED] http://www.blackriveractionteam.org ~Making ripples on the Black River since 2000! ~