Roundup Runoff Lethal to Amphibians

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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.

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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 biod
iversity 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@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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