Removal of invasive floating pennywort Hydrocotyle ranunculoides from Gillingham Marshes, Suffolk, England

  • Published source details Kelly A. (2006) Removal of invasive floating pennywort Hydrocotyle ranunculoides from Gillingham Marshes, Suffolk, England. Conservation Evidence, 3, 52-53.


This study is summarised as evidence for the following.

Action Category

Floating pennywort: Physical removal

Action Link
Control of Freshwater Invasive Species
  1. Floating pennywort: Physical removal

    A study in 2005-2006 by the Broads Authority at Gillingham Marshes, Suffolk, UK (Kelly 2006) found that removal of floating pennywort Hydrocotyle ranunculoides using a mechanical digger and extensive hand picking, along with monitoring, greatly reduced the cover of floating pennywort but did not completely eradicate it.  Hand-picking was undertaken at least once a month (usually every fortnight) throughout the growing season (March – September 2005-2006 ongoing). In addition, a mesh grid was added to the upstream end of the water pump at Gillingham Marshes to try to prevent floating fragments from entering and infesting the River Waveney, adjacent to the marshes.  To dispose of the pennywort, it was piled on the site and monitored for regrowth. Monthly monitoring of the pile was undertaken and if signs of growth were observed, they were sprayed with the herbicide glyphosate.

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