Neonicotinoid pesticides have for years caused controversy over their impacts on pollinating insects, but a new study now focuses on their effects on the aquatic life in our watercourses.
The winding Waveney acts as the border between Suffolk and Norfolk for much of its length - but there is nothing borderline about this iconic, much-loved river when it comes to its level of contamination with perhaps the most controversial of all insecticides currently used in British agriculture.
The Waveney has gained an unwanted Christmas Number One spot - it has been named as the UK watercourse with the most neonicotinoid, or neonic, contamination of any tested in recent research. Its “disgraceful pollution” features strongly in a new report on the issue by the invertebrate conservation charity Buglife. The newly published document is based on the results of monitoring carried out in 2016 by the Environment Agency as part of Britain’s responsibilities under the EU Water Framework Directive.
Most of the huge amount of controversy surrounding neonics in recent years has focused on their impacts on pollinating species - a common shorthand reference to them has been “bee-harming insecticides”. Indeed, neonics were banned from use on flowering crops in the EU in 2013, although Suffolk was one of four UK counties where such a restriction was lifted temporarily in 2015 to enable application on oil seed rape crops. An extension of the ban to cover all outdoor uses may follow soon following yet more evidence of the harm caused to pollinators.
But Buglife points out: “Aquatic insects are just as vulnerable to neonicotinoid insecticides as bees and flying insects, yet have not received the same attention because the UK Government has not responded to calls to introduce systematic monitoring.
“However, under the EU Water Framework Directive Watch List initiative the UK was required to introduce a pilot monitoring scheme for all five commonly used neonicotinoids – Imidacloprid, Clothianidin, Thiamethoxam, Acetamiprid and Thiacloprid. Twenty-three sites were sampled in 2016, 16 in England, four in Scotland, three in Wales and three in Northern Ireland (the latter’s data has yet to be released to the public.)”
The charity added: “Eighty-eight per cent of sites in Britain were contaminated with neonicotinoids, eight rivers in England exceeded recommended chronic pollution limits, and two were acutely polluted. Populations of mayflies and other insects in these rivers are likely to be heavily impacted, with implications for fish and bird populations.
“The River Waveney on the Norfolk/Suffolk border was the worst polluted river with the acute harm level exceeded for a whole month and the River Wensum in Norfolk, a Special Area of Conservation for its river life, was also chronically polluted. These rivers supply the Broads, an internationally important wetland site and home to many endangered aquatic animals. Sugar beet fields are the most likely source of pollution in these rivers.”
Aquatic invertebrate populations represented an important part of the UK’s biodiversity, providing valuable ecosystem services, recycling organic matter
and keeping rivers clean, the report says. In addition, they provided essential food for fish and birds.
Neonics were “widely used” insecticides with three main applications in the UK - as a seed coating for field crops, as sprays for crops and domestic gardens, and as an externally applied arthropod parasite treatment for pets.
The chemicals were water-soluble, mobile and could persist for months or years - as a result they had been found polluting waterbodies around the world, with mayflies, caddisflies, flies and beetles tending to be “most sensitive” to neonic pollution.
On a list of rivers failing their chronic pollution limits, the Waveney and Norfolk’s Wensum are said in the report to be polluted with both Clothianidin and Imidacloprid.
Report author Matt Shardlow, Buglife’s chief executive officer, said: “We are devastated to discover that many British rivers have been heavily damaged by neonicotinoid insecticides. It is vital that action is taken to completely ban these three toxins, including in greenhouses and on pets, before another year of disgraceful pollution occurs.”
He told eaenvironment: “The Environment Agency is to be congratulated for the thorough job it has done with its monitoring.”
More widely, he said: “It’s been painful over the last few years, with all the evidence piling up about the effects these things were having on bees and the Government putting its head in the sand and sticking its fingers in its ears. But it is now good to see that it is refreshing its position and looking at the overwhelming evidence of harm and showing support for a wider ban.”
Buglife was this week sending a list of recommendations to Defra and the Environment Agency.
It called for monitoring of the five most commonly used neonics to continue, regardless of their future Watch List status, and the number of sites and sample dates expanded. It wants a comprehensive EU-wide ban on the agricultural use of Imidacloprid, Clothianidin and Thiamethoxam “due to the harm they are causing to the aquatic environment.” There was “no obvious alternative way to reduce or mitigate their impact on aquatic life.”
It also urged “urgent action” to reduce Imidacloprid pollution in water bodies and return them to “good chemical condition”.
The Environment Agency should “develop a clear regulatory approach to responding to neonicotinoid pollution” and “Defra should establish an initiative to transform insecticide environmental risk management so as to ensure future generations have a better protected environment.”
The full report can be viewd on Buglife’s website.
Next week: Suffolk naturalists’ neonic fears revealed, and agriculture’s view.
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