[permaculture] [Fwd: [SANET-MG] roundup kills frogs and tadpoles]

Lawrence F. London, Jr. lfl at intrex.net
Fri Aug 5 07:46:50 EDT 2005

-------- Original Message --------
Subject: [SANET-MG] roundup kills frogs and tadpoles
Date: Fri, 5 Aug 2005 07:02:49 -0400
From: jcummins <jcummins at UWO.CA>

August 3, 2005 Contact: Karen Hoffmann
klh52 at pitt.edu

Roundup® Kills Frogs As Well As Tadpoles, Pitt Biologist Finds
PITTSBURGH—As amphibians continue to mysteriously disappear worldwide, a
University of Pittsburgh researcher may have found more pieces of the
puzzle. Elaborating on his previous research, Pitt assistant professor
of biological sciences
Rick Relyea has discovered that Roundup®, the most commonly used
herbicide in the world, is deadly to tadpoles at lower concentrations
than previously tested; that the presence of soil does not mitigate the
chemical’s effects; and that the product kills frogs in addition to

In two articles published in the August 1 issue of the journal
Ecological Applications, Relyea and his doctoral students Nancy
Schoeppner and Jason Hoverman found that even when applied at
concentrations that are one-third of the maximum concentrations expected
in nature, Roundup® still killed up to 71 percent of tadpoles raised in
outdoor tanks.

Relyea also examined whether adding soil to the tanks would absorb the
Roundup® and make it less deadly to tadpoles. The soil made no
difference: After exposure to the maximum concentration expected in
nature, nearly all of the tadpoles from three species died.

Although Roundup® is not approved for use in water, scientists have
found that the herbicide can wind up in small wetlands where tadpoles
live due to inadvertent spraying during the application of Roundup®.

Studying how Roundup® affected frogs after metamorphosis, Relyea found
that the recommended application of Roundup® Weed and Grass Killer, a
formulation marketed to homeowners and gardeners, killed up to 86
percent of terrestrial frogs after only one day.

“The most striking result from the experiments was that a chemical
designed to kill plants killed 98 percent of all tadpoles within three
weeks and 79 percent of all frogs within one day,” Relyea wrote.

Previous studies have determined that it is Roundup®’s surfactant
(polyethoxylated tallowamine, or POEA, an “inert” ingredient added to
make the herbicide penetrate plant leaves) and not the active herbicide
(glyphosate) that is lethal to amphibians.

This research was funded by the National Science Foundation, Pitt’s
McKinley Fund, and the Pennsylvania Academy of Science.


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