While recent research (and media attention) has focused on the alleged negative impacts of pesticides on bees, the problem may be far broader according to a new study in the Proceedings of the US Academy of Sciences (PNAS). Looking at over 50 streams in Germany, France, and Australia, scientists in Europe and Australia found that pesticide contamination was capable of undercutting invertebrate biodiversity by nearly half.
“Pesticide use has not decreased in the last decade […] and is predicted to increase in the next decades due to climate change and thus may be a more important driver of biodiversity loss in the future,” the scientists write.
By comparing 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 Europe. Meanwhile in Australia, freshwater biodiversity fell by 27 percent between clean and contaminated streams.
Pesticide contamination hit some invertebrate groups the hardest including dragonflies, stoneflies, caddisflies, and mayflies. Such species did not necessarily disappear altogether, but saw their abundance plunged. While, many of the decimated species may not be well-known to the general public, they play a major role in the food chain, including as prey for birds and fish.
Notably, current regulations in Europe are not strong enough to protect these species, according to the scientists. They found that even in those contaminated sites that met EU regulations, biodiversity had plunged. This points to a rising controversy over proper testing and risk assessments for pesticides before they released into the public’s hands.
“The current practice of risk assessment is like driving blind on the motorway,” says co-author, Matthias Liess, an ecotoxicologist with the Helmholtz Centre for Environmental Research in Germany.
In April, the EU banned three pesticides for two years in a bid to stem bee losses on the continent. A flood of recent studies have shown an increasingly convincing connection between a type of pesticides, known as neonicotinoids, and colony collapse disorder (CCD) in bees. The pesticides likely don’t kill the bees outright, but instead impair brain functioning leading to navigational and other problems, which is exacerbated by habitat and food loss as well as disease.
Insect species such as the Common Bluetail (Ischnura senegalensis) are particularly threatened by pesticide entries in their habitat. Photo by: André Künzelmann/UFZ (Place: Banaue/Phillippines).
CITATION: Beketov, M., Kefford, B., Schäfer, R., & Liess, M. PNAS. Pesticides reduce regional biodiversity of stream invertebrates. 2013.
(06/18/2013) A widely used insect nerve agent has been labelled a “high acute risk” to honeybees by the European Food Safety Authority (EFSA). A similar assessment by the EFSA on three other insecticides preceded the suspension of their use in the European Union.
(05/29/2013) On 15 April more than 100 fishermen demonstrated in the streets of Fort de France, the main town on Martinique, in the French West Indies. In January they barricaded the port until the government in Paris allocated €2m ($2.6m) in aid, which they are still waiting for. The contamination caused by chlordecone, a persistent organochlorine pesticide, means their spiny lobsters are no longer fit for human consumption. The people of neighboring Guadeloupe are increasingly angry for the same reason. After polluting the soil, the chemical is wreaking havoc out at sea, an environmental disaster that now threatens the whole economy.
(05/09/2013) Nearly a third of managed honeybee colonies in America died out or disappeared over the winter, an annual survey found on Wednesday. The decline—which was far worse than the winter before—threatens the survival of some bee colonies. The heavy losses of pollinators also threatens the country’s food supply, researchers said. The US Department of Agriculture has estimated that honeybees contribute some $20bn to the economy every year.
(04/29/2013) The EU has banned three neonicotinoid pesticides (imidacloprid, clothianidin and thiamethoxam) linked to the decline of bees for two years. The ban will apply to all flowering crops, such as corn, rape seed, and sunflowers. The move follows a flood of recent studies, some high-profile, that have linked neonicotinoid pesticides, which employ nicotine-like chemicals, to the widespread decline of bees seen both in Europe and North America.
(04/10/2013) New Zealand’s Department of Conservation (DOC) is facing a backlash over plans to aerially drop a controversial poison, known as 1080, over the habitat of two endangered, prehistoric, and truly bizarre frog species, Archey’s and Hochsetter’s frogs, on Mount Moehau. Used in New Zealand to kill populations of invasive mammals, such as rats and the Australian long-tailed possum, 1080 has become an increasingly emotive issue in New Zealand, not just splitting the government and environmentalists, but environmental groups among themselves. Critics allege that the poison, for which there is no antidote, decimates local animals as well as invasives, while proponents say the drops are the best way to control invasive mammals that kill endangered species like birds and frogs and may spread bovine tuberculosis (TB).
(03/27/2013) Exposure to commonly used pesticides directly disrupts brain functioning in bees, according to new research in Nature. While the study is the first to record that popular pesticides directly injure bee brain physiology, it adds to a slew of recent studies showing that pesticides, especially neonicotinoids, are capable of devastating bee hives and may be, at least, partly responsible for on-going Colony Collapse Disorder (CCD).
(03/19/2013) The global farmland area certified organic has expanded more than threefold to 37 million hectares since 1999, according to new research conducted by the Worldwatch Institute. The Institute argues that organic farming has the potential to contribute to sustainable food security by improving nutrition intake and sustaining rural livelihoods, while reducing vulnerability to climate change and enhancing biodiversity.
(02/05/2013) Following a flood of damning research on the longterm impact of neonicotinoid pesticides on bee colonies, the EU is proposing a two year ban on the popular pesticides for crops that attract bees, such as corn, sunflower, oil seed rape, cotton. The proposal comes shortly after European Food Safety Authority (EFSA) released a report that found neonicotinoid pesticides posed a “number of risks” to bees.
(01/28/2013) Commonly used agrochemicals (pesticides, fungicides and herbicides) kill frogs outright when sprayed on fields even when used at recommended dosages, according to new research in Scientific Reports. Testing seven chemicals on European common frogs (Rana temporaria), the scientists found that all of them were potentially lethal to amphibians. In fact, two fungicides—Headline and Captain Omya—wiped out the entire population of frogs at the recommended dosage. The study warns that agricultural chemicals could be having a large-scale and largely unrecorded impact on the world’s vanishing amphibians.
(10/24/2012) The evidence that common pesticides may be partly to blame for a decline in bees keeps piling up. Several recent studies have shown that pesticides known as “neonicotinoid” may cause various long-term impacts on bee colonies, including fewer queens, foraging bees losing their way, and in some cases total hive collapse. The studies have been so convincing that recently France banned the use of neonicotinoid pesticides. Now a new study finds further evidence of harm caused by pesticides, including that bees who are exposed to more than one chemical, i.e. neonicotinoid and pyrethroid, were the most vulnerable.