Pesticide threat to biodiversity underestimated

Pesticides may kill off water insects and other small aquatic life by as much as 42%, according to an analysis of German, French and Australian rivers and streams published on Monday.

Dragonflies are particularly vulnerable to pesticides

Dragonflies are particularly vulnerable to pesticides

The study in US journal the Proceedings of the National Academy of Sciences is the first to compare regional biodiversity in polluted versus less polluted water, said scientists at the Helmholtz Association of German Research Centres.

Freshwater invertebrates and aquatic insects were 42% less common in strongly contaminated areas in Europe compared to less polluted areas; and in Australia, a difference of 27% was found across regions.

The analysis included measurements of insecticides and fungicides, which are used often in agriculture and are typically well studied and heavily regulated.

However, the researchers said little examination has been done to gauge their effect on the streams and rivers they end up in after it rains and the chemicals are washed off farmland and into watercourses.

“The current practice of risk assessment is like driving blind on the motorway,” said ecotoxicologist Matthias Liess, a study co-author.

Species that were particularly vulnerable to pesticides included dragonflies, stoneflies, mayflies and caddis flies.

The researchers warned that the threat pesticides pose to biodiversity has been underestimated, since experimental lab work and studies on artificial ecosystems often precede a pesticide’s market approval.

“The effects in Europe were detected at concentrations that current legislation considers environmentally protective,” said the study, calling for new approaches to better assess the ecological risks of pesticides.

A better practice would be to assess the ecological impact of chemicals by investigating real environments on a larger scale, the authors said.

The findings show that UN goals to slow down the decline in biodiversity by 2020 are “jeopardised,” it said.

Source: AFP

Research claims organic farming harms wildlife

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 09 May 2010

South Africa’s organic farming industry is up in arms over international research that claims organic farming harms wildlife and produces less food – and that its produce is no healthier than conventionally farmed foods.

The popularity of organic foods – produced naturally without pesticides and potentially harmful fertilisers – has soared in South Africa in recent years.

But research conducted by the University of Leeds in England found that organic farms produced less than half as much food compared with conventional farming and needed twice as much land to produce the same amount of food.

The study also showed there were 10% fewer small birds, such as yellowhammers, corn buntings, linnets, skylarks and lapwings, in organic fields in the UK. Researchers found that larger birds, which were attracted to dense organic crops, were scaring away the smaller birds, disrupting the ecosystem.

But that was not the worst of it. A recent review commissioned by the UK Food Standards Agency found that organic food was neither more nutritious nor healthier than conventionally farmed food.

Said the agency’s Gill Fine: “This study does not mean that people should not eat organic food. What it shows is that there is little, if any, nutritional difference … there is no evidence of additional health benefits from eating organic food.”

But local experts have slammed both reports. Durban agricultural scientist Dr Raymond Auberbach said that, contrary to the study’s findings, organic farming was beneficial to birdlife, adding that conventional farming methods were wiping out birds of prey. Continue reading