Author`s name Timothy Bancroft-Hinchey

Pesticides: Biodiversity at risk

This week's edition of Nature magazine brings a chilling article on the horrendous effects of agricultural chemicals in pesticides on invertebrates and the soil. The key words:  even at 'safe' levels. The results were drawn from several studies in different continents and reveal that in polluted areas, up to forty-two per cent of species were lost as a result of harmful chemicals.

The article in this week's Nature magazine, "Pesticides spark broad biodiversity loss", written by Sharon Oosthoek, tells a sorry tale of the effects of pesticides on biodiversity. The conclusion is that the use of pesticides has caused a sharp decline in the biodiversity of invertebrates living in streams. Studies carried out in Germany and France in Europe and in Australia showed a dramatic decline in species such as mayflies and dragonflies.

Quoting he study published in the Proceedings of the National Academy of Sciences, Sharon Oosthoek went on to state some shocking details: the studies were carried out in 23 streams in Germany, 16 in France and 24 in Australia, classifying them in three categories: uncontaminated, slightly contaminated and highly contaminated.

In the last category, there were up to 42% fewer species than those found in the uncontaminated group of streams in Europe, while the figure in Australia was a decrease of 27%. More seriously still, the article goes on to claim, the decrease in biodiversity occurred even at levels which scientists state to be "environmentally protective".

As usual, the scientific community is divided. Some are quoted in the same piece as claiming that we are at "crisis point", while there are others who state that this type of situation is only a worst case scenario, unrepresentative of the majority of streams.

However, the article quotes a second study with equally alarming results - the effects of neonicotinoid pesticides on bees - the European Commission has ordered a ban of two years on three common types of neonicotinoid pesticides because of this.

This study was performed by David Goulson on the University of Sussex, whose research revealed that these pesticides can accumulate in soil, killing invertebrates. This is affecting not only the soil, according to the article, but also the birds which feed on these invertebrates.

This being the case, the decline in the bee population could be the tip of the iceberg. And who is at the top of the food chain?

Timothy Bancroft-Hinchey