Roundup highly lethal to amphibians - may explain global decline

[Guest guest]

GMW: Roundup highly lethal to amphibians - may explain global

decline

 

" GM WATCH " <info

Tue, 5 Apr 2005 09:02:59 +0100

 

 

 

GM WATCH daily

http://www.gmwatch.org

------

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

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. "

 

 

---------------------