Professor Dave Goulson, who spoke at a packed Pollinator Project event in Guernsey last year, has released research that found toxic insecticides in 99% of samples from rivers in England and the average level of one particularly toxic breakdown product of the pesticide was 38 times above the safety limit.
Fipronil and another nerve agent called imidacloprid that was found in the rivers have been banned from use on farms since 2017 and 2018 respectively.
The washing of pets was already known to flush fipronil into sewers and then rivers, while dogs swimming in rivers provides another pathway for contamination.
Research also highlighted that aquatic insects are known to be vulnerable to neonicotinoids and Dutch research has shown chronic waterway pollution led to sharp drops in insect numbers and falls in bird numbers. Aquatic insects are also declining due to other pollution from farms and sewage, with just 14% of English rivers in good ecological health.
The Guernsey Pollinator Project reacted to the article and said: ‘We’ve grown accustomed to a variety of noxious and toxic chemicals in our everyday lives from algicides to clean our paths, anti-fouling treatments for our boats, to flea and tick treatments for our pets.
‘Add in the anti-wormers and weedkillers and fly sprays and it should be no surprise that the numbers of butterflies, bees and other beneficial insects are in steep decline across the world. Guernsey is not immune to Covid and it’s not immune to these effects either.’
This new research from Professor Goulson shows that the active ingredients in flea and tick treatments persist in our environment and get into streams and rivers.
The research points out that the chemicals are not allowed for use in agriculture, but are used on cats and dogs.
With between 16,000 and 20,000 cats and dogs in Guernsey that represents a lot of pesticide in our homes and natural environment.
Professor Goulson pointed out that just one imidacloprid-based flea treatment for a medium-sized dog contains enough pesticide to kill 60 million bees.
While they may get washed out into the sea that shouldn’t mean ‘out of sight, out of mind’ says Gordon Steele of the Pollinator Project.
He said that more research is needed but recommends that thought is given to making these products prescription only.
‘We support a precautionary approach but also think the first step for Guernsey should be to capture sales data for all the pesticides sold on island.
‘We also recommend pet owners look for alternatives to using chemicals and only using flea and tick treatments when they are actually needed – not as preventatives.
‘It’s easy to forget when your pet was last treated or to add in an extra dose before friends come round. This risks contamination of the environment as well as harm to your pets,’ he said.