CORRECTION: The currently known range of the 'lionfish' does not extend to N of Cape Cod. So it is RI, not NH. Thanks to David Duffy for bringing the error to my attention Apologies. As to the many interesting comments following my post, I appreciate them all. Given that ecosystems are dynamic, changing baselines is a reality. My thesis is not that alien species should be introduced. It is that a fresh view is called for. I definitely hold that efforts should be directed at avoiding introductions.
That is supported by the numerous examples of adverse outcomes of purposeful introductions to 'solve' an ecological problem. Others may be accidental introductions. The years of debate on the introduction of alien oysters into the Chesapeake Bay has left behind a question: If we consider Crassostrea virginica is a keystone species that provides a range of eco-services and that it is also socio-economically important, then its demise is a serious ecological loss. With the descision to not introduce C. ariakensis, possibly based on the negatives associated with the experiences with C. gigas, was a chance to improve the health of the Bay missed? At this point the operating hypothesis is to cultivate disease resistant (naturally resistant) C. virginica - native. Many of us spend winter months searching the bottom on scuba for live oysters. This approach is highly commendable and is in keeping with maintaining the integrity of an ecosystem. But will it solve the problem. Will the 1% of original population return to a sustainable population that provides the suite of ecological services ascribed to it. Or will other species provide some of those services (clam?). Will novel approaches to cultivation take up the slack? That said, the possible positive outcome of C. ariakensis introduction remains unknown, and is an experiment that is best left not done. But the lack of an answer remains disturbing - That is: there is reason to bring a systems, multi factorial approach to modeling new baselines, and base descisions on those models, not on individual species. Unfortunately there is no single answer as many of the issues that have to be considered as at times they trancend science - socio-economics, policies, politics, stakeholders, all become part of the assessment. Hence the call for a new look at established dogma. Not necessarily disown them, but reevaluate them. Esat Atikkan --- On Fri, 6/10/11, David L. McNeely <[email protected]> wrote: From: David L. McNeely <[email protected]> Subject: Re: [ECOLOG-L] EcoTone: Speaking of species and their origins To: [email protected] Date: Friday, June 10, 2011, 2:45 PM ---- Katie Kline <[email protected]> wrote: > An essay published in the June 8 issue of Nature is causing something of a > stir. Eighteen ecologists who signed the essay, titled "Don't judge species > on their origins," "argue that conservationists should assess organisms based > on their impact on the local environment, rather than simply whether they're > native," as described in a recent Scientific American podcast. > > In the essay, Mark Davis from Macalester College, St. Paul, Minnesota and > colleagues argue that adherence to the idea of non-natives as "the enemy" is > more a reflection of "prejudice rather than solid science," wrote Brandon > Keim in a Wired Science article. As the authors wrote, the "preoccupation > with the native-alien dichotomy" among scientists, land managers and > policy-makers is prohibitive to dynamic and pragmatic conservation and > species management in a 21st century planet that is forever altered by > climate change, land-use changes and other anthropogenic influences. As a > result of this misguided preoccupation, claim the authors, time and resources > are unnecessarily spent attempting to eradicate introduced species that > actually turn out to be a boon to the environment; the authors cite the > non-native tamarisk tree in the western U.S. as an example of this... > > Read more and comment at > http://www.esa.org/esablog/ecologist-2/speaking-of-species-and-their-origins/ Exactly how have tamarisks (there are two invasive species in the western U.S. unless I have been misinformed) been a "boon to the environment"? They have displaced native willows and cottonwoods. Their transpiration rates far exceed those of the native species they replace, lowering the water table in the area and drying streams, playas, and cienagas. By concentrating salts in their foliage, then dropping the foliage to the ground, they increase the salinity of surface soils. Animal species that depend on the riparian vegetation they displace lose out. So do those that depend on the streams and cienagas as aquatic habitat. mcneely
