Pesticides punish biodiversity

There are around about nine million unique living organisms on this small third rock from an undistinguished sun. One of those organisms happens to be us: Homo sapiens. You could look at humans and think they stand at the top of this organic pile and, indeed, that is exactly what many humans have done for a long while. There are evolutionary elements of truth in that view but it is also an incomplete view because without these organisms and the ecosystems and processes that they sustain, human societies could not exist. The organisms of Earth supply oxygen and clean water, cycle carbon, fix nutrients, enable plants to grow, keep diseases in check and regulate climate. The biodiversity of the planet is essential to human survival and yet at most turns we seem dedicated to eradicating that diversity of life. In fact, a new report spanning Europe and Australia has shown that pesticide use is drastically diminishing biodiversity in our rivers and streams.

The researchers gathered data on 16 streams in France, 23 streams in Germany and 24 streams in Victoria, Australia. Based on the data the researchers matched pesticide levels in the water with the number of different species in the streams.

According to pesticide levels the streams were classified as uncontaminated, slightly contaminated or highly contaminated. Across the globe, in both Europe and Australia, there were major differences in biodiversity between areas of no contamination and those of high contamination. In Europe biodiversity was reduced by as much as 42 per cent in areas of high contamination while in Australia it was reduced by as much as 27 per cent.

It is important to note that these changes are occurring at levels of pesticide that are deemed “safe” by current European legislation. The main organisms affected were found to be stoneflies, caddisflies, mayflies and dragonflies. Of course, these flies are important members of the food chain that leads to fish and birds. So these current “safe” levels are apparently not adequate to protect biodiversity in flowing waters.

The researchers make the point that pesticides currently gain approval for use based on laboratory and artificial ecosystem tests. It would seem that “real world” testing should be the least that is demanded or we may not have much real world left.