(Beyond Pesticides, March 7, 2016) A United Nation’s report, released late last month, has warns the world that many species of wild bees, butterflies and other pollinators are on a dangerous path toward extinction, and that the food supply will suffer if the causes of these declines, many of them human-made, are not stopped. The report is based on many different scientific studies. The scientists who led the assessment pointed to pesticides as one of the leading causes of pollinator decline, specifically, a class of toxic chemicals called neonicotinoids, which adversely affect the nervous system of insects.
According to their press release, the assessment, Thematic Assessment of Pollinators, Pollination and Food Production, is the first ever issued by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). IPBES was founded in 2012 with 124 member nations to “form a crucial intersection between international scientific understanding and public policy making.”
Before its release, the assessment attracted some controversy for including two representatives from the agrochemical industry, including Bayer CropScience and Syngenta, as lead authors. Even though the IPBES requires all lead authors to complete conflict-of-interest statements, some scientists and environmentalists expressed concern. Given the roll of agrochemicals in pollinator decline, some believe that scientists funded by the pesticide industry should not be allowed to take part in these types of assessments, which are meant to be unbiased. That said, the report did highlight the role of pesticides in pollinator decline.
The assessment found that an estimated sixteen percent of vertebrate pollinators are threatened with global extinction — increasing to thirty percent for island species – with a trend towards more extinctions. Although most insect pollinators have not been assessed at a global level, regional and national assessments indicate high levels of threat, particularly for bees and butterflies – with often more than 40 per cent of invertebrate species threatened locally. The assessment also found that pesticides, including neonicotinoid insecticides, threaten pollinators worldwide. Other factors that the report pointed to as contributors for pollinator declines included pests, diseases, genetically modified crops and the decline of farming practices that are based on indigenous and local knowledge.
The science on bee health has demonstrated that even small, low-dose (sublethal) neonicotinoid exposures can have detrimental effects on bees. In 2015, researchers found that bumblebees exposed to field levels of neonicotinoids accumulate the toxic pesticides in their brains, and acute and chronic exposure increase neuronal vulnerability to mitochondrial dysfunction. Other studies on the subject reveal a clear link between these chemicals and the synergistic effects they have on bees when combined with parasites and disease, such one published by Di Presco et al. (2013), which found that the neonicotinoid clothianidin reduces insect immunity, and promotes viral replication in honey bees by up to 1,000-fold, after exposure to field-realistic and sublethal doses. A review of recent literature concludes that the weight of evidence “strongly confirms that systemic insecticides, notably the neonicotinoids”¦, are the primary factor in the death of millions of bee colonies globally.”
The report also cites the vast economic importance of pollinators and pollinator services. According to the press release, seventy-five percent of the world’s food crops depend at least in part on pollination. The annual value of global crops directly affected by pollinators is estimated to be $235 to $577 billion, and the annual honey production from the western honey bee is 1.6 million tonnes.
In conclusion, researchers pointed to numerous options that could be implemented to safeguard pollinators, such as maintaining or creating greater diversity of pollinator habitats in agricultural and urban landscapes, supporting traditional practices in agriculture, such as crop rotation, and utilizing other indigenous local knowledge, and decreasing exposure of pollinators to pesticides by reducing pesticide usage, seeking alternative forms of pest control, and adopting specific application practices.
While industry may argue that bee-toxic pesticides, such as neonicotinoids, are necessary for agricultural output and pest control, these claims have not been proven. In August 2015, reports out of the UK found that the country was poised to harvest higher than expected yields of canola in its first neonicotinoid-free growing season since the European moratorium on neonicotinoids went into place in 2013. According to the UK’s Agriculture and Horticulture Development Board (AHDB) Harvest Report, with 15% of canola harvested, yields are between 3.5 and 3.7 tons per hectare, higher than the normal farm average of 3.4.
Relying on the promotion of chemical-intensive agricultural practices is not a sustainable solution. In addition to the impact that pesticides have on pollinators, these chemical inputs can contaminate waterways, leading to eutrophication and “dead zones,” where nothing is able to live or grow. Chemical-intensive agriculture also depletes organic matter in the soil and undermines biological systems necessary to sustain life. Conversely, increasingly organic agriculture is understood as a sustainable agricultural system that restores and regenerates the environment and long-term security. Organic agriculture is not only necessary in order to eliminate the use of toxic chemicals, it is necessary to ensure the long-term sustainability of food production, ecosystem functionality, and the economy.
In order to make a difference at home, declare your garden, yard, park or other space pesticide-free and pollinator friendly. It does not matter how large or small your pledge is, as long as you contribute to the creation of safe pollinator habitat. Sign the pledge today! Need ideas on creating the perfect pollinator habitat? The Bee Protective Habitat Guide can tell you which native plants are right for your region. For more information on what you can do, visit our BEE Protective page.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.