Posted on 08/11/2005 9:07:52 AM PDT by GreenFreeper
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, University of Pittsburgh 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 chemicals effects, and that the product kills frogs in addition to tadpoles.
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, Pitts McKinley Fund, and the Pennsylvania Academy of Science.
*****
Complete Citation
THE LETHAL IMPACT OF ROUNDUP ON AQUATIC AND TERRESTRIAL AMPHIBIANS Ecological Applications 15(4): 1118-1124 Rick A. Relyea Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
Abstract. The global decline in amphibian diversity has become an international environmental problem with a multitude of possible causes. There is evidence that pesticides may play a role, yet few pesticides have been tested on amphibians. For example, Roundup is a globally common herbicide that is conventionally thought to be nonlethal to amphibians. However, Roundup has been tested on few amphibian species, with existing tests conducted mostly under laboratory conditions and on larval amphibians. Recent laboratory studies have indicated that Roundup may be highly lethal to North American tadpoles, but we needed to determine whether this effect occurs under more natural conditions and in post-metamorphic amphibians. I assembled communities of three species of North American tadpoles in outdoor pond mesocosms that contained different types of soil (which can absorb the pesticide) and applied Roundup as a direct overspray. After three weeks, Roundup killed 96100% of larval amphibians (regardless of soil presence). I then exposed three species of juvenile (post-metamorphic) anurans to a direct overspray of Roundup in laboratory containers. After one day, Roundup killed 6886% of juvenile amphibians. These results suggest that Roundup, a compound designed to kill plants, can cause extremely high rates of mortality to amphibians that could lead to population declines.
Species used: Bufo maericanus, Hyla versicolor, Rana pipiens
*****
A gratis downloadable pdf of this and other current papers by Relyea is available from the CNAH PDF Library on the CNAH web site home page at:
http://www.cnah.org/cnah_pdf.asp
I find this worrisome, but apparently the frogs on my place are resistant - there are a ton of them. I use Round-Up some, not a lot. I use a specific grass killer a lot (an over the top type) and I know it has a "soap/sticker" ingredient also. Actually, almost anything you spray outdoors for use on plants will have such an ingredient.
I just never know how much faith to put in these studies - there is so much junk science.
The point remains that RoundUp is a problem for frogs far from aquatic areas (we have them 600 yards from and 200 feet in elevation above the nearest stream). Your post left the impression that if people used RoundUp far from aquatic areas and reserved Rodeo for aquatic use there would be no problem. That is not true when aquatic animals are found far from aquatic areas.
Rodeo doesn't have a surfactant system. You need to add it youself. Several studies have shown LI 700, Induce, and X-77 pose little risk to aquatic organisms. When that is added, Rodeo works just as well as Roundup, if not better.
Thanks for the information. I have never used Rodeo as I am far from an aquatic area and thus had no need. One problem however: I have called ALL of the ag chemical suppliers in this area (which includes Wilbur Ellis in the Salinas Valley, one of the largest distributors of ag chemicals in the world) and NONE of them sell any of those surfactants. I would bet that they would be pricey, perhaps doubling the cost of use.
I agree completely. I think sometimes I don't explain my points well- just saying it does not surprise me in the least that Roundup is bad for amphibians. The key is avoiding the overspray. If properly applied (stem treatment)I imagine most critters would be unaffected.
One problem however: I have called ALL of the ag chemical suppliers in this area (which includes Wilbur Ellis in the Salinas Valley, one of the largest distributors of ag chemicals in the world) and NONE of them sell any of those surfactants. I would bet that they would be pricey, perhaps doubling the cost of use.
I don't remember them being pricey. We mostly used LI 700 and I believe it was ~ $20 a gallon. A gallon goes a long way. I will see if i can find our supplier post the details.
Maybe this will help?
http://www.junkscience.com/
Just to show you how old-school I am...we had Frogger for the Commodore 64, in cartridge format, with that crapassed black joystick with one button.
It was awesome. Today's 3D shootemups got nothing on some of these arcade classics.
Does this mean that they can start charging more?
No telling what "Paraquat" does to them....
We went with TrueNorth. Here is a link to their price list. $8.90 a Liter or $178.00 a case. Pretty comparable to other surfactants.
http://www.truenorthspecialty.com/english/2005pricebook1.pdf
To you maybe. To me, as an end user buying from a distributor in California, most surfactants are about twice that.
A gallon goes a long way. I will see if i can find our supplier post the details.
It depends upon the target species. If it's a grass, it takes very little (unless it's lolium). If it's a member of the spurge family such as scarlet pimpernel, it takes about half as much as the active. If it's an ivy, or a vinca, it takes a LOT, even with pre-abrasion of the plant surface.
As to preventing overspray, the risk varies with the chemical system. You will often see reccomendations for low nozzle pressure, which does allow for larger droplets. However, those larger droplets can splatter or bounce more easily than smaller droplets. I use a xanthan gum thickener which is highly thixotropic, but has no extensive viscous component. Thus I get clean droplet separation and minimize satellite droplets on formation but get less shatter on impingement. That thixotropy gives me wide latitude in formation characteristics, with the ability to generate high shear at high nozzle pressures providing small droplets to penetrate a thick shrub, and lower shear for larger droplets that shatter less on impingement for spot application.
I am extremely dissatisfied with sprayers designed for wildlands applications. If I get my design business going again, I'm going to do something about that. I hold a patent for a spray coated exam glove that used controlled droplet application with air classification to control log bimodal droplet size distributions.
That fits my typical budgetary ballpark number for adjuvants at $40 a gallon. I seriously doubt TrueNorth would sell to a California resident.
I'd bet that Monsanto will soon have a recommended system as well.
A surfactant "wets" the surface allowing the product to stay on the leaves long enough to be absorbed into them and systemically work down to the roots; the surfactant alone allows the first appearance of dying while the root uptake finishes the job.
The larval frogs and the juveniles were the most seriously affected probably because the surfactant causes the skin to bead water and interferes with the natural surface "breathing."
Spraying the frogs and tadpoles or the trap they are in does not truly represent field conditions as the instructions clearly suggest you spray only when rain is not forecast for 24 hours and tells you not to water after use.
Sadly, too many scientists can't leave their biases or their tongues holstered.
bump
It is historically not beyond Monsanto to seek regulatory means to control a market. The patent on glyphostate just ran out a couple of years ago. So it is not mere tinfoil to see the possibility in NSF funding of this research as a freon redux. It's just awfully hard to tell.
My chief complaint is that a regulatory risk management architecture is opaque to political manipulation, not to mention too often destructive to its justifying precepts, favoring instead continued power and perquisites for its paper-pushing oligarchy. Needless to say, today's grant-mongering professorate is not above dependent complicity therewith, however often unconscious. It's just not a system capable of producing implicitly trust-worthy data, as you noted.
This information is not new. Surfactants kill almost everything, even ants, aphids, and roaches. It invades their shells and stops their metabolism instantly. I don't use anything at all near the ponds; I want all the aquatic life (except skeeters) on our property to thrive, and won't take any chances, even with mosquito cakes.
I'll second that emotion. We constantly find tree frogs in our bedroom, and kitchen, 100 feet above, and 300 feet away from the nearest pond. Skinks can also be found is some very dry places.
I buy the stuff without the surfactant and add a little dish soap. It's cheaper, serves the same function (reduces the surface tension of the water) and it works just as well.
Many chemicals can be absorbed through the skin.
Does it say exactly how the frogs die?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.