Larry,

Hatchery fish can and do spawn in the wild. The USF&WS introduced
"hatchery" Gambusia on a waterfowl pond on Ankeny NWR, Marion Co. Oregon
several years ago. The pond maintains a self-supporting population of
these live-bearers, the seasonal ditch below the pond supports these fish
whenever there is water in the ditch, and the ditch flows to the
Willamette River which has a plethora of channels and sloughs tailor-made
for Gambusia habitat. In 1988 I collected gravid females from this pond.

Are these fish providing forage for native birds? Certainly!

Are these fish competing with native fish - such as the endemic Oregon
chub (Hybopsis crameri)? Potentially and likely probably!

Do exotic species belong in our wild environments? Not No - Hell No!

"Weeds", whether flora or fauna, are impacting the natural ecology of the
Northwest to the point of crisis. The loss of natural diversity to
invasive exotic species is on-going in practically every ecological
system one can study in the Northwest. Millions of dollars will be spent
this year to 'control' invasive plants, exotic shellfish compete with
native clams and oysters, rats get into my compost pile and starlings
fight with the violet-green swallows at the nest box. The exotic
_Spartina_ has the potential to vegetate the mudflats that our shorebirds
depend upon. Exotics are not the answer, and I for one do not trust the
assurances of my colleagues that mosquitofish, grass carp and tiger
muskellunge are the quick-fix for environmental problems.

If the principle for biological control does merit serious concern, it
should be undertaken with the tools at hand. There
are plenty of native cyprinid and other fish species with which to
stock ponds for mosquito control. The native species and habitats of
this region are under constant pressure from introduced exotic species,
and these habitats are degraded for our avifauna by invasive plants. I
do not see the introduction of an exotic species (Gambusia) to "control" a
native species (mosquito) as aesthetically or morally conscionable. If
people don't want to get bitten, they should stay indoors....

Jon. Anderson
Olympia, WA
anderjda at dfw.wa.gov


On Thu, 13 Apr 1995, McCloskey, Lawrence R wrote:

> Appreciate the expressed concern about introduction of exotic species. The
> principal is worthy of serious concern. But the strains of Gambusia the F & W
> have used are hatchery-reared, and there's enough case history data to show
> beyond any reasonable doubt that these are non-threatening species,
> short-lived (normally you have to re-introduce the population every year), and
> a prey specialist on insect larvae like mosquitoes. To eschew such a
> biologically sound control possibility because of unwarranted extrapolation
> from other bona fide horror stories (the Starling story is not a good
> parallel), especially in favor of unnatural chemical biocides, may not be
> prudent.