With mass farming comes unwanted evils in the form of weeds and insects. In the old days weeds were pulled and when they came back, pulled again (insects were kept at bay by netting). But now, with farming large plots of land becoming a big business, pesticides and herbicides have come into the equation. In the past if agricultural chemicals were used on crops they would be killed, which is a main reason why it wasn’t done in such high volumes as it is today. With the invention of genetically modified crops that are resistant to these chemicals, such as GM soy beans and GM cotton (95% of cotton is GM), their death is no longer an issue. But for everything else that doesn’t have this genetically modified characteristic, it means desolation and death.
A recent study in the Proceedings of the National Academy of Sciences found that in water contaminated with pesticide biodiversity greatly dropped, “Researchers found that there were up to 42% fewer species in highly contaminated than in uncontaminated streams in Europe. Highly contaminated streams in Australia showed a decrease in the number of invertebrate families by up to 27% when contrasted with uncontaminated streams” (nature.com). Earthworms, which help loosen soil to allow nutrients and water to fall deeper into the ground and also enrich the soil with their slimy secretions, and bees, which help pollinate, have seen a dramatic population loss in recent years. With the extensive use of herbicides "super weeds" have surfaced. These "super weeds" overtake other vegetation and kill native biota which results in increasing levels of herbicide usage.
The only way to stop this deadly cycle is to stop using agricultural chemicals. This would allow native fauna to grow as it has in the past and insure the survival of our diminishing invertebrate/vertebrate species variations.