The Ver Valley Society’s volunteers are instrumental in monitoring the River Ver’s health by recording the invertebrate levels every month.
We’ve adopted the Riverfly Partnership’s citizen science scheme in which trained volunteers take a monthly sample at 18 regular locations along the Ver from the confluence with the Colne (Bricket Wood) to Luton Lane (Redbourn). We extend upstream of Luton Lane when there is water in the upper Ver.
River invertebrates, such as caddis fly larvae, mayfly nymphs and freshwater shrimp, are caught in a net by kick sampling for three minutes at a specified site. A score is calculated by measuring the number of species and their abundance. This generates a seasonal baseline of the biological quality of the river. This can be used to monitor change, especially as our records now date back to 2013.
Each site has a ‘trigger score’ derived from its past performance and falling below this level usually indicates a pollution incident and the Environment Agency is informed.
We have a full complement of monitors at present. If you would like to go onto the reserve list to sample Riverfly along the Ver, please contact John Pritchard (Ver Riverfly Co-ordinator) and we hope to be able to send you for training once a vacancy occurs.
Further information can be viewed at the Riverfly Partnership’s Website.