Pesticides have been found in 85 per cent of rivers tested in England, an analysis of government statistics has revealed.
Green groups looked at Environment Agency data on neonicotinoid pesticides in river basins that were tested between 2023 and 2024.
The chemical damages the nervous system of bees and studies show that aquatic insects and mayflies are also at risk, which could affect the abundance of fish and birds in the diet.
Although neonicotinoids are banned in Europe, they are allowed to be used annually in the UK from 2021.
The figures show an increase in affected rivers, from 79 percent in 2020 to 2022.
Areas where sugar beet production is concentrated – particularly in the East Midlands and the East of England – had the highest figures.
Sugar beet is a plant whose root contains a large amount of sucrose and is cultivated commercially to produce sugar. Products also include meat products made from leftover pulp.
Seedlings and young plants are vulnerable to viruses that can reduce their growth and lower sugar levels. In 2020, a quarter of the UK’s sugar crop was lost, costing £67million in total economic losses.
The River Waveney at Geldeston, Norfolk. Around 85 per cent of rivers tested in England have been found to contain pesticides.
Large numbers were found at the same site on the River Waveney and River Wensum (pictured)
The largest concentrations were found at the same site on the River Waveney and River Wensum in the East Midlands, where all five neonicotinoids tested were found.
Other sites found include the River Nene in the East of England, the River Lugg, the River Tame in the West Midlands, the Sincil Dyke in the East Midlands, the River Ouse in Yorkshire, the River Test in the South East, the River Chelt in the South West and the River Douglas in the North West.
Campaigners also noted that only 27 rivers across England were tested for pesticides in 2023-24, down from 43 sites in 2020-2022, representing a drop of more than a third in the number of sites tested.
They warned that this is a sign of the deterioration of the resources of the Environmental Agency and the lack of monitoring of the river by the manager.
During this summer’s election, Sir Keir Starmer said: ‘The new government will ban the neonicotinoid pesticides imidacloprid, clothianidin and thiamethoxam because of their effects on bees.’
But British Sugar and the National Farmers’ Union (NFU) have asked to be allowed to use the neonicotinoid Cruiser SB on sugar beet, which fights the plant disease known as virus yellows.
If approved, it will be the fifth year in a row of emergency use of neonicotinoids.
Cruiser SB is based on the pesticide thiamethoxam, which is extremely toxic to bees – just one teaspoon is enough to kill 1.25 billion.
The River Test (photographed in Overton, Hampshire) was among the waterways with the most neonicotinoids
Richard Benwell, chief executive of Wildlife and Countryside Link, said: “The Government should reject this proposal and extend farming reforms to provide generous support to farmers who reduce their use of pesticides.
‘The concentration of powerful pesticides in rivers is another smoking gun in the hands of intensive agriculture and environmental degradation.’
Barnaby Coupe, director of land use policy at the Wildlife Trusts, said: ‘The UK Government’s pledge to end emergency pesticide use must be signed into law.
‘Pollination from insects such as bees is the basis of a healthy ecosystem and is essential for pollination and seed production.
These chemicals are banned because they are very dangerous to soil, water, wildlife and human health.
‘The evidence is clear that the environmental risks from neonicotinoids are too great – there is no place in today’s society for their use.’
A Defra spokesman said: ‘We are committed to tackling all sources of pollution to clean up our rivers, lakes and seas.
‘This government has been clear that we will change existing policies to stop the use of neonicotinoid pesticides that threaten bees and other important pollinators.’
