In his article, “Agriculture
exacts a price in the High Sierra,” Cosmo Garvin has indicted
California’s Central Valley agriculture for the decline of
frogs in the Sierra Nevada (HCN, 5/26/03: Agriculture exacts a
price in the High Sierra). Despite the fact that pesticide residues
found in mountain frogs are far below lethal levels, the argument
seems to be that since declines in frog populations have occurred
in mountain regions downwind from agricultural regions, pesticides
are responsible.
It is worth noting that these mountain
regions are also downwind of large human populations and sources of
SO2, NOx, ozone, photochemical smog and other emissions. I would
suggest that at this juncture it would make about as much sense to
blame the demise of the frogs on backyard barbecue grills.
There are some other problems with the pesticide hypothesis.
Synthetic organic pesticides have been used for more than half a
century. If pesticides constitute the culprit, why didn’t the
frog populations decline long ago, particularly since pesticide
applications are now regulated far more stringently?
Also,
Lassen Volcanic National Park lies downwind of the Sacramento
Valley, while Sixty Lakes Basin (in Kings Canyon National Park) is
downwind of the San Joaquin Valley. Cropping patterns are very
different in the two areas. The principal crop in the Sacramento
Valley is rice, while cotton is the main crop in the San Joaquin
Valley. The same pesticides are not generally used on
both.
This is a sorry excuse for scientific
research.
Donald F. Anthrop
San José,
California The author is a professor of environmental studies at
San José State University.
This article appeared in the print edition of the magazine with the headline Pesticides killing frogs? Poppycock..
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