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 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]
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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
This email address is being protected from spambots. You need JavaScript enabled to view it.
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."