As I said, the lamprey was a contributing cause -- the final stressor in an
already stressed system -- that subsequently has shouldered much if not all
of the blame.
> kind of like how the carp is blamed
> for the decline of other game fish, when in fact it was introduced as a
> replacement species to natives that were disappearing due to habitat
> destruction.
Excellent analogy, Mark! Here's some background on this for those who don't
know the true story of the all-too-common carp:
Carp were first brought to North America by immigrating Europeans who simply
wanted to bring a taste of the Old World with them. When and where carp
first entered North America is a matter of conjecture. Some evidence
suggests that carp were cultured in New York in the 1830s; other evidence
suggests these fish were actually goldfish. The first confirmed propagation
of carp in the U.S. was in 1872, when a Sonoma, California resident imported
five specimens from Germany and cultured them in private ponds for sale as
food. From these five specimens a profitable business flourished, news of
which spread to entrepreneurs and gourmands around the country who wanted
carp to stock in their own private ponds. The newly formed U.S. Fish
Commission (precursor to the U.S. Fish and Wildlife Service) took notice.
Realizing that the country's inland fishery had begun to decrease due to
overharvest and pollution, the Commission viewed carp as a desirable sport
and food fish that would flourish in America's deteriorating waters. In 1877
the Commission imported 345 carp from Germany. Over the next 20 years,
hundreds of thousands of government-issue carp per year were distributed
throughout the country. Congressmen actually vied with one another to see
who could get the most carp for their constituents!
The carp loved America. By the turn of the 20th century, carp had
established themselves in just about every drainage system in which they
were introduced, and were well on their way to becoming the most abundant
fish in the inland waters of North America.
At the same time, however, America stopped loving the carp.
It wasnąt the carp's fault. In Europe, special strains of superior-tasting
carp are raised in large, clean ponds. In America, carp were being raised in
just about anything that contained water, including ponds filled with
treated sewage effluent. The result was a muddy tasting fish that few wanted
to eat. In a striking feat of environmental self-denial, Americans began
blaming carp for the poor quality of the waters in which the fish lived, and
for the declining populations of other game fishes such as bass and sauger.
As carp angling enthusiast Tom Dickson put it, "The carp was the perfect
scapegoat. It was foreign. It was thriving. And it couldnąt defend itself."
This is not to say that carp are an entirely benign presence. Carp will prey
on the eggs of other species and, as such, have been implicated in the
declines of razorback sucker in the Colorado River basin and white sturgeon
in the Columbia River. The carp's penchant for dislodging plants can destroy
native fish spawning and nursery areas, while their rooting through mud can
increase turbidity and thereby reduce light for photosynthesis. But because
carp have been around ever since scientists began collecting data on fish
abundance, their total impact on the American fish fauna may never be known.
What is known is that carp rarely make waters inhospitable to other fishes.
Instead, it is humans who have made waters inhospitable to fishes other than
carp. Once established, carp are expensive if not impossible to eliminate.
As long as rivers are dammed, channelized, muddied from eroded and treeless
river banks, and tainted with industrial and human wastes, America will
always be home to the uncommonly adaptable common carp.
Chris Scharpf
Baltimore
/-----------------------------------------------------------------------------
/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
/ Association"
/ This is the discussion list of the North American Native Fishes Association
/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
/ nanfa-digest-request_at_aquaria.net instead.
/ For more information about NANFA, visit our web page, http://www.nanfa.org