Kick Samples

In conjunction with the Riverfly Partnership, CATCH now undertakes regular monitoring of the health of the River Cale by a process known as kick sampling in which certain key river-dwelling invertebrates are identified and counted. The Riverfly Partnership focuses on three key groups of riverflies: the up-wing flies or mayflies (Ephemeroptera), caddisflies or sedges (Trichoptera) and stoneflies (Plecoptera). These riverflies live most of their lives as larvae on the beds of rivers and still waters, emerging as short-lived adult flies mostly in spring and summer, often en masse.   There are a total of 278 species of mayflies, caddisflies and stoneflies, of which eight species have Biodiversity Action Plan status and therefore are recognised as a priority for conservation.

Ideally, kick sampling is carried out monthly.  However, conditions during the winter months can make this difficult and may also disturb fish spawning sites. Although this has to be weighed against lack of monitoring, CATCH, along with other registered monitoring groups, generally now carries out kick samples April – October.

Kick sampling is carried out at specific sites which are registered with the Riverfly Partnership. The two currently registered for the River Cale in Wincanton are at The Beach (below Waterside) and under the A303 flyover.  We hope to add another site further downstream in the future.

After sampling, the numbers of each invertebrate found at each site are entered onto the Riverfly Partnership website (www.riverflies.org).   From these numbers a score is calculated for each site and compared with a low score trigger level set by the Partnership.  If the site score drops to, or below, the trigger level the process must be repeated a week later.  If results are still at or below the trigger level the Riverfly Partnership alerts the Environment Agency to investigate what has caused the loss of invertebrate life.

The beauty of the riverfly kick sampling process is that volunteers and members of the public can participate with minimal training.  Come and get involved!  Anyone is welcome to come along, although be advised that accessing the A303 site involves climbing over two fences and getting down a steep 8 foot concrete ramp (with the aid of a rope) so a certain level of agility and fitness is required! The site at Wincanton Beach is much more accessible.

Kick samples are scheduled for the morning of the second Sunday of the month although this may vary if water levels are too high.   When possible exact details will be posted on the CATCH Facebook page (@RiverCaleCatch) &/or announced on this website.