Impact of neonics in the River Waveney unknown, says EA
PUBLISHED: 13:32 11 June 2018 | UPDATED: 13:44 11 June 2018
JULIAN CLAXTON PHOTOGRAPHY
A manager at the Environment Agency has said it is difficult to know what impact pesticides, including neonicotinoids, have had on aquatic life, after one Suffolk river was acutely polluted with the chemicals.
The EA’s catchment delivery manager for Suffolk, Will Akast, was speaking at a meeting of the Suffolk Coastal Friends of the Earth group in Saxmundham last week.
The group had invited Mr Akast to give a presentation after invertebrate charity Buglife reported late last year that the River Waveney on the Suffolk/Norfolk border had been ‘acutely polluted’ and the River Wensum in Norfolk ‘chronically polluted’ by neonicotinoid pesticides.
Buglife based its report on testing data from 2016 - the Waveney and the Wensum both flow through areas designated as Catchment Sensitive Farming Sites (CSF) and the rivers underwent testing twice a week to monitor for the presence of the five commonly used neonicotinoids, which have now been banned from use outdoors, following an EU-wide ruling on the controversial insecticides in April.
A spike in the presence of a number of neonicotinoids, primarily Clothianidin and Thiamethoxam, was recorded at Ellingham Mill on the Waveney for June 2016 - meaning the acute harm level was exceeded for a whole month at the location.
But Mr Akast said; “It is difficult to know what impact pesticides have on aquatic life” and pointed to a host of other factors that can also affect the health of fish and water invertebrates.
Changes in water flows, sedimentation, eutrophication - brought about by fertilisers, and the presence of other harmful chemicals - such as those found in sun cream - can all affect the health of aquatic life, he said.
Other factors include the presence of micro-plastics and invasive species.
“It’s too complicated a picture to be definite about the impact of one pesticide,” added Mr Akast.
Mr Akast said no legal action had taken place as a result of the test results but he said the Environment Agency had continued to work with farmers and landowners to mitigate the problem of pesticides being used in fields and running off into nearby rivers.
“We offer advice and guidance first and only then do we go down the enforcement route,” he said.
Some “practical, on the ground measures” farmers are being advised to consider include the planting of reed beds to act as a natural filter; the installation of buffer strips - a margin of farmland near a waterway that isn’t treated with pesticides to provide a natural barrier; and the planting of trees near rivers to stall run off and to increase biodiversity in rivers because of the shade they provide.
“The dappled shade from trees can knock two to three degrees off the temperature of a river,” said Mr Akast who pointed out that the presence of polluting substances, including neonicotinoids, in rivers is not solely caused by the activities of farmers.
He said a “disproportionate” amount of pollution comes from the run off from horse paddocks while slug pellets employed by gardeners and flea collars used by pet owners both contain neonicotinoid chemicals.