Floating Pennywort eradication

Graphic stating Pebble - projects that explore biodiversity benefits in the local environment

Cam Valley Forum applied to the 2017-18 PEBBLE grant for its project on eradicating floating Pennywort on the Upper Cam.

Invasive and fast-growing floating Pennywort grows as a dense tangle of plants, blocking sunlight from getting into the river, impacting native wildlife and also making stretches of the river impassable for recreational activities, such as fishing, punting and boating.

The Cam Valley Forum project team worked from two large punts to clear overhanging trees from the river, as the floating Pennywort would often become entangled in drooping branches. They also removed large clumps of Pennywort. Several areas were made into habitat refuges for birds, such as moorhens and dabchicks, as well as providing shelter for fish too. These habitat refuges were protected from Pennywort on the upstream side, using prototype booms installed by Cambridge Canoe Club.

The project was awarded £4,385 from Cambridge Water’s PEBBLE grant and was also funded and supported by eight other organisations, including the Environment Agency. 

The Cam Valley Pennywort projectThe project had: 
  • Two giant punts on loan from Scudamores for seven weeks in February and March
  • 95 days of professional effort
  • 100 reported volunteer hours, with more hours to be reported
  • 2.8km length of treeworks completed, originally applied for 0.6km length
  • No visible floating Pennywort at the end of this initial phase, with just a few very small fragments noticed by May
  • Cam Valley Forum has also registered an additional eight volunteers through the project