Riverfly Monitoring

Riverfly Monitoring

In 2007 the Association began a systematic programme of riverfly monitoring. The reason for this is twofold. Firstly we can begin to build a much better understanding of the invertebrate life that exists in the river and what this can tell us about the health of the river and its capacity to hold wild fish. Secondly we can offer information to members about the species present at different locations and seasons so that they can better match the artificials they use to the predominant prey species. We can learn much more from these studies such as whether the conservation measures we are taking are helping to increase the populations of invertebrate species and if so which ones. This is vital if we are to succeed in our plans to make this a truly self sustaining wild fishery.

We began by doing some training. Six members and the keeper gathered at Horton pavilion in May 2007 for a day’s intensive course in riverfly capture and identification techniques. This was a fascinating experience and showed that the river at Horton is clean, healthy and teeming with riverfly. We had an inspirational teacher in Dr Nick Everall who supervised 7 gentlemen of mature years reverting to small boys given the chance to play with water, lots of bugs, a microscope and magnifying glasses. The event was sponsored by the Wild Trout Trust to whom we owe a real debt of thanks.

Immediately following this course we set about buying the equipment necessary to do our own monitoring and selected key sites to survey.

We now do a standard six month survey at three sites: New Inn Bridge, Cragg Hill and Selside. These are the beats most frequently fished as well as being dispersed along the fishery and offering a variation in habitat and substrate. Selside is particularly important as it lies in the newly created buffer strip and will show us over time whether the erection of the fence and planting of trees here has delivered any change in riverfly numbers or range of species.

In addition we do a monthly bankside check at Turn Dub and New Inn Bridge. Again, Turn Dub is a beat with good bankside fencing and recent extensive tree planting. The aim is to record findings against eight key species that are used nationally in riverfly monitoring programmes. In fact we will monitor nine species as our first sample has shown that we have a recordable number of Turkey Browns present which are fairly rare nationally and indicate very clean water.