Tillingbourne Riverfly Monitoring

Invertebrate Monitoring

Over the years many anglers, especially flyfishers, have noticed an apparent decline in the numbers of hatching riverflies, particularly in upwinged flies, caddis and stoneflies. There are many stories from the Tillingbourne Valley and beyond of the tremendous mayfly and caddis hatches of the past.

It was thus of great interest to several of the Albury Estate anglers that The Riverfly Partnership was formed to "bring together anglers, conservationists, entomologists, scientists, water course managers and relevant authorities to increase our knowledge, expertise and understanding of riverfly populations".

One of the main initiatives of the partnership is to encourage countrywide angling groups to find out 'what is in their river' and to regularly monitor invertebrate numbers using a simple and standardised method of sampling.

With this in mind, and after talks with Dr Cyril Bennett and The Frensham Flyfishers (a pioneering group on the River Wey) plus members of the Peper Harrow Flyfishers Club, a number of Albury anglers decided to set up their own monitoring group on the River Tillingbourne.

With the kind permission of the Duke of Northumberland and Albury Estate a small group started monitoring in 2005. This has now grown to eight or more enthusiastic anglers with numbers on the increase.

One of the first steps in setting up the group was to attend a 'River Invertebrate Monitoring for Anglers' one-day workshop at Leckford. This was based on the monitoring methodology developed by Cyril Bennett and it gave invaluable help in identifying the various invertebrate species, along with hands-on instruction on how to obtain the sample from the river.

This was followed by a meeting with the Environment Agency’s local contact to give advice on suitable locations for our monitoring sites. Two locations were chosen with very obviously different habitats. One is at the very top of our stretch of river and surrounded by trees and is rather shaded with little bank-side vegetation and river weed - not a very popular fishing spot. The other site is further downstream in a far more open location with a variety of habitats, altogether a far 'fishier' spot.

The group is now monitoring monthly throughout the fishing season (April to the end of September) and less frequently during the winter months. The results are recorded and shared with the local Environment Agency's Ecological Appraisal Officer. This has provided a seasonal baseline for the invertebrate population of our river, which can be used to monitor any changes in water quality and if necessary ensure appropriate action is taken.