|Roundup canisters. CC photo by London Permaculture on Flickr|
More than twenty years after the commercialisation of GM crops designed to be blanket-sprayed with 'Roundup' herbicide, a paper has been published showing that a single spraying put earthworms at risk of local extinction.
Earthworms are a key part of the creation of the soil's mineral-organic complex particles on which its fertility and biological integrity depend. Because earthworms don't disperse widely, local extinction is a long-term environmental catastrophe, especially if "local" is the size of a typical GM monoculture. To the Argentinean environmental scientists who carried out the belated earthworm experiment, 'local' means nearly 66% of their country's cropping surface which is planted almost entirely with GM 'Roundup Ready' soya.
Their experiment was low-tech, short, and needed expertise only in handling earthworms and in identifying them at all stage of their life-cycle. Common worms, of a kind regularly used as experimental models, were put into pots of earth with plant-litter, and sprayed once with either water, Roundup at the usual agricultural concentration, or Roundup at a double-dose. Sample-pots were analysed at intervals for their total earthworm population (i.e. eggs, young, plus adults). Further tests for egg fertility were carried out.
What they found was that the earthworms were annihilated by the sixth week after a single exposure to Roundup. Routine toxicity tests which typically look for acute effects within two to three days, or subchronic effects within seven to seventeen days, are clearly inadequate to reveal Roundup's harm to earthworms. Worse, at agricultural concentrations, Roundup stimulated population growth during the first two weeks: this is a common response in wild-life subject to environmental stress but would lead to a false impression of 'no harm' in a short-term toxicity study. Exposure to double-dose Roundup led to a small early minimal population decline which could also be dismissed as unimportant.
The study highlighted that the most sensitive marker for Roundup damage was the number of young earthworms reaching adult-hood: more usual measurements such as effects on adults and eggs could give a false impression of Roundup's effects.
In a situation where Roundup spraying is increasing in both frequency and concentration due to emerging weed resistance, coupled to a loss of regeneration of the soil due to the annihilation of earthworms, 66% of Argentina's cropping area is likely to enter a state of complete biological collapse, and stay that way for a very long time.
Earthworms are exceptionally thoroughly exposed to Roundup in a GM field. As they feed, they will ingest Roundup attached to soil particles and organic matter, especially organic matter derived from root tips in which Roundup accumulates. Any spray which misses, or runs off, the plants ends up in soil water where it will bath the worms' skin. The glyphosate herbicidal ingredient of Roundup typically persists in the soil for 60 days after which the earthworms are likely to be gone.
How Roundup could be killing earthworms hasn't been investigated, but there are lots of possiblities already suggested by experiments on other animals.
For example, glyphosate is an antibiotic and likely to disturb the microbe balance in the soil which the worms are eating and the microflora in the worms' gut. Also, glyphosate immobilises essential minerals making them unavailable to the body which leads to malnutrion and immune-system weakness, and it has neurotoxic and endocrine disruptive effects which can impact negatively on the physiology and on essential animal behaviour.
Roundup has, in addition to glyphosate herbicide, added chemicals to aid penetration into the living cell: these could be attacking the earthworm from the outside and inside, and could be assisting the entry of many other environmental toxins to which the animals are exposed.
Twenty years seems a long time to get around to setting up a few pots of soils with worms to check whether one of the soils' most important inhabitants is in danger.
Scientists are spending a incredible amount of cash analysing entire profiles of DNA, the RNA it produces, the proteins generated by the DNA and RNA, and all the biochemicals which play a part in the physiology. They have access to an infinity of molecular data with an infinity of meanings, from which they're trying to extract a working definition of 'harm' and 'safety' in GM plants and in the animals which eat them.
The earthworms-in-a-pot experiment suggests it might be worth putting more attention on what's actually happening to whole animals in a realistic model environment, and extend the time of their studies.
Zero worms means zero fertile soil means zero food means zero people. All the high-tech ultra-reductionist science in the world won't get rid of these zeros: but a bit of holistic science and farming will.
- Eat organic and local whenever possible.
- Check out The Permaculture Association (Scotland). www.permaculture.org.uk/scotland
- join The Soil Association (Scotland) to help it work on your behalf for the health of food and farming. http://www.soilassociation.org/scotland
- Martina Santadino, it al., 2014, Glyphosate Sublethal efects on the Population Dynamics of the Earthworm Eisenia fetida (Savigny, 1826), Warter Air Soil pollution 225
- Dr. Don D Huber, Yet Another Suspect in CCD/Dwindling? Center for Honeybee Research, www.gmoevidence.com, August 2013