Press release

Keep an eye out for floating pennywort this winter

We’re asking river-users to report any new outbreaks of the invasive plant

Pennywort Wey
Removing floating pennywort from the River wey in Surrey in 2017

Pennywort thrives in the summer, but the Environment Agency is urging rivers users to not be complacent about reporting new outbreaks of this invasive and destructive plant over the winter months.

In July, the Environment Agency reported more than 63 tonnes had been removed from the River Thames earlier in the year – a great result thanks to the co-operation of partners and key members of the community.

However, now that winter is fast approaching and fewer people are out on the river, the message for those who continue to brave the cold is to remain alert and help nip fresh outbreaks in the bud.

Daryl Buck, from the Environment Agency, said:

The Environment Agency and our local partners have been working hard to manage and monitor the spread of Floating Pennywort in 2018 and because of this good work we have had to remove significantly less of it than in 2017. This reduced growth shows that we are starting to get the spread of this invasive plant under control, but we are not getting complacent and we know that, with everyone’s help, we will need to continue our efforts for several years to come.

We would like to thank Thames river-users who have reported fresh sightings to us so far. However, winter means fewer people are on the river keeping an eye out. We are urging riverside owners, anglers, boaters, canoeists - anyone who still enjoys the river in the colder months - to continue being vigilant and report any new growth to us.

Together with local partners the Environment Agency actively monitors more than 200km of the River Thames and its tributaries. The overall aim is to eradicate floating pennywort from the Thames. Large blooms of the plant affect the oxygen content of rivers, reduce biodiversity, can damage important habitats and potentially increase flood-risk.

Eradication of floating pennywort can only be achieved with the continued co-operation of the river community. Vigilance over the winter months will ultimately help to reduce the spread over the summer when plants can grow up to 20cm a day in the warmer temperatures.

Ian Penny, secretary of a local angling club, said:

The efforts of the Environment Agency in removing floating pennywort from the Abbey river has really paid off and currently this invasive species has not returned in anything like the quantity previously experienced.

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Published 16 November 2018