Once a month several RevIvel members head off with a large net and a bucket to various points on the upper River Ivel. They are off to collaborate with the Environment Agency and Riverfly Partnership in the overall monitoring of the abundance of riverfly life.
A good indication of the state of the river can be discovered. A three-minute kick sample is taken in the river with the net pinpointing different habitats such as the clear gravelly parts and the greenery in the river or at the side. The contents of the net are put into a bucket and carried back to one of the members gardens to sort and also drink coffee! There are lots of ‘oohs and aahs’ as they are sorted by tipping gently into a large white tray and then separate the invertebrates by type into a segmented white tray. Then they are counted and come up with an abundance score.
The target groups are as follows: Caddisflies (both cased and caseless), Up-Winged Flies (Mayfly etc), Stoneflies and Freshwater Shrimp. There is a bit of competition to find the
handsomest caddis fly. They make their own home using tiny stones, green leaves and even bits of plastic. Small fish are exciting too and this week water beetles and water crickets were found. Seeing a leech extend from its smallest to largest size is fascinating.
Riverfly monitoring gives an insight into the Ivel’s invertebrates, their cycles and environmental needs.
Images are as follows
Top left CADDIS
Top right CADDIS using plastic and gravel for its case
Botton left LEECH
Bottom right SHRIMP
