[permaculture] [Fwd: [SANET-MG] more on frog doom]

Lawrence F. London, Jr. lfl at intrex.net
Tue Apr 5 10:01:49 EDT 2005



-------- Original Message --------
Subject: 	[SANET-MG] more on frog doom
Date: 	Tue, 5 Apr 2005 08:00:19 -0400
From: 	jcummins <jcummins at UWO.CA>
Reply-To: 	Sustainable Agriculture Network Discussion Group 
<SANET-MG at LISTS.IFAS.UFL.EDU>
To: 	SANET-MG at LISTS.IFAS.UFL.EDU



1.Roundup Herbicide Runoff Is Lethal To Amphibians
2.Roundup® highly lethal to amphibians, finds University of Pittsburgh
researcher

EXCERPT: This field experiment is one of the most extensive studies on
the effects of pesticides on nontarget organisms in a natural setting,
and the results may provide a key link to global amphibian declines.
------
1.Roundup Herbicide Runoff Is Lethal To Amphibians
Posted on Mon Apr 4th, 2005

The herbicide Roundup is widely used to eradicate weeds, particularly
around genetically engineered crops that have been given the
controversial genes of immunity to this chemical. The patented
"Roundup-ready gene" is currently being put in every single crop type
you can imagine, and is resulting in skyrocketing Roundup herbicide use.

Unfortunately, it looks like frogs don't have a Roundup-ready gene,
which is too bad considering they have no choice but to live and breed
in watersheds and run-off zones.

A study published today by a University of Pittsburgh researcher finds
that the chemical may be eradicating much more than weeds. Pitt
assistant professor of biology Rick Relyea found that Roundup, the
second most commonly applied herbicide in the United States, is
extremely lethal to amphibians.

This field experiment is one of the most extensive studies on the
effects of pesticides on nontarget organisms in a natural setting, and
the results may provide a key link to global amphibian declines.

In a paper titled "The Impact of Insecticides and Herbicides on the
Biodiversity and Productivity of Aquatic Communities," published in the
journal Ecological Applications, Relyea examined how a pond's entire
community--25 species, including crustaceans, insects, snails, and
tadpoles--responded to the addition of the manufacturers' recommended
doses of two insecticides--Sevin (carbaryl) and malathion--and two
herbicides--Roundup; (glyphosate) and 2,4-D.

Relyea found that Roundup caused a 70 percent decline in amphibian
biodiversity and an 86 percent decline in the total mass of tadpoles.
Leopard frog tadpoles and gray tree frog tadpoles were completely
eliminated and wood frog tadpoles and toad tadpoles were nearly
eliminated. One species of frog, spring peepers, was unaffected.

"The most shocking insight coming out of this was that Roundup,
something designed to kill plants, was extremely lethal to amphibians,"
said Relyea, who conducted the research at Pitt's Pymatuning Laboratory
of Ecology. "We added Roundup, and the next day we looked in the tanks
and there were dead tadpoles all over the bottom."

Relyea initially conducted the experiment to see whether the Roundup
would have an indirect effect on the frogs by killing their food source,
the algae. However, he found that Roundup, although an herbicide,
actually increased the amount of algae in the pond because it killed
most of the frogs.

"It's like killing all the cows in a field and seeing that the field has
more grass in it--not because you made the grass grow better, but
because you killed everything that eats grass," he said.

Previous research had found that the lethal ingredient in Roundup was
not the herbicide itself, glyphosate, but rather the surfactant, or
detergent, that allows the herbicide to penetrate the waxy surfaces of
plants. In Roundup, that surfactant is a chemical called polyethoxylated
tallowamine. Other herbicides have less dangerous surfactants: For
example, Relyea's study found that 2,4-D had no effect on tadpoles.

"We've repeated the experiment, so we're confident that this is, in
fact, a repeatable result that we see," said Relyea. "It's fair to say
that nobody would have guessed Roundup was going to be so lethal to
amphibians."

>From a UPMC press release
http://www.eurekalert.org/pub_releases/2005-04/uopm-rhl040105.php [see
below]
------
2.Roundup® highly lethal to amphibians, finds University of Pittsburgh
researcher
Public release date: 1-Apr-2005
http://www.eurekalert.org/pub_releases/2005-04/uopm-rhl040105.php

Contact: Karen Hoffman
klh52 at pitt.edu
412-624-4356
University of Pittsburgh Medical Center

PITTSBURGH--The herbicide Roundup® is widely used to eradicate weeds.
But a study published today by a University of Pittsburgh researcher
finds that the chemical may be eradicating much more than that.

Pitt assistant professor of biology Rick Relyea found that Roundup®, the
second most commonly applied herbicide in the United States, is
"extremely lethal" to amphibians. This field
experiment is one of the most extensive studies on the effects of
pesticides on nontarget organisms in a natural setting, and the results
may provide a key link to global amphibian declines.

In a paper titled "The Impact of Insecticides and Herbicides on the
Biodiversity and Productivity of Aquatic Communities," published in the
journal Ecological Applications, Relyea examined how a pond's entire
community--25 species, including crustaceans, insects, snails, and
tadpoles--responded to the addition of the manufacturers' recommended
doses of two insecticides--Sevin® (carbaryl) and malathion--and two
herbicides--Roundup® (glyphosate) and 2,4-D.

Relyea found that Roundup® caused a 70 percent decline in amphibian
biodiversity and an 86 percent decline in the total mass of tadpoles.
Leopard frog tadpoles and gray tree frog tadpoles were completely
eliminated and wood frog tadpoles and toad tadpoles were nearly
eliminated. One species of frog, spring peepers, was unaffected.

"The most shocking insight coming out of this was that Roundup®,
something designed to kill plants, was extremely lethal to amphibians,"
said Relyea, who conducted the research at Pitt's Pymatuning Laboratory
of Ecology. "We added Roundup®, and the next day we looked in the tanks
and there were dead tadpoles all over the bottom."

Relyea initially conducted the experiment to see whether the Roundup®
would have an indirect effect on the frogs by killing their food source,
the algae. However, he found that Roundup®, although an herbicide,
actually increased the amount of algae in the pond because it killed
most of the frogs.

"It's like killing all the cows in a field and seeing that the field has
more grass in it--not
because you made the grass grow better, but because you killed
everything that eats grass," he said.

Previous research had found that the lethal ingredient in Roundup® was
not the herbicide itself, glyphosate, but rather the surfactant, or
detergent, that allows the herbicide to penetrate the waxy surfaces of
plants. In Roundup®, that surfactant is a chemical called
polyethoxylated tallowamine. Other herbicides have less dangerous
surfactants: For example, Relyea's study found that 2,4-D had no effect
on tadpoles.

"We've repeated the experiment, so we're confident that this is, in
fact, a repeatable result that we see," said Relyea. "It's fair to say
that nobody would have guessed Roundup® was going to be so lethal to
amphibians."







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