Pesticides Gutting Dragonfly Populations In VIC
Pesticides are shattering a vital link in the food chain by significantly reducing the populations of Dragonflies. The effect was found in streams in Germany, France, and Australia.
A new study in the Proceedings of the US Academy of Sciences (PNAS) compared freshwater species in uncontaminated streams with those in highly-contaminated streams.
The researchers found that invertebrate biodiversity dropped by 42 percent in polluted streams in the Europe samples. In southern Victoria, freshwater biodiversity dropped by 27 percent between clean and contaminated streams.
The hardest-hit invertebrate groups were found to be dragonflies, stoneflies, caddisflies, and mayflies. These species did not disappear, but their numbers were significantly reduced. And that means less food for birds, frogs, and fish, not to mention fewer predators of harmful creatures such as mosquito larvae.
The scientists say tighter regulations are needed to protect the Dragonflies, because the streams tested in Europe fully met the current environmental standards.