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Invertebrate Survey

The club is fortunate that at regular intervals during the year a survey of the invertebrate life in the river is carried out. This not only gives us valuable indicators as to the health of the river ...but also some clues as to what flies to use! The 2020 surveys noted that:-

"Great news, I completed June's invertebrate survey on Friday and the river is looking in exceptional condition. After low numbers in early March, I thought this would impact the season. However the reverse. It was one of the best samples I've taken on the river. Alas I could only do Small Bridge and Harpers this time, but results were great in both. 


Small Bridge

Excellent diversity of invertebrates. Predominantly caseless caddis, olives and blue winged olives. I also picked up a few shrimp and good showing of stonefly. All indicates really good water conditions. While I was sampling a number of mayfly were coming off too. All in all I would expect some fine evening fishing action over the coming weeks on dry flies. 


Total number of invertebrates was 217, significantly higher than last year


Harpers (above the old weir)

Good showing of caseless caddis, olives and blue winged olives. I also saw some heptigeniidea and stone fly. All indicating good water conditions. I also spotted a lot of fry. I can see this piece of water developing well over the coming years, if we maintain the quality of conditions I picked up on this sampling. 


Harpers (between stream and lower bridge)

Very similar to above the weir, but with a bit more mayfly. It scored 144 in total. Twice as many since the same time last year. 


In conclusion I think members will be experiencing some good sport over the summer and they should definitely try the river in the evening for maximum opportunity for dry fly fishing. "


I completed a survey in October for Small Bridge and Harpers. In general the river looks fine for this time of year. At this time of year, you don't find huge volumes of invertebrates as many will be in egg form waiting for the coming new season. In general Caseless caddis and olives made a good show, with a few shrimp and heptageniids making a show. 


As I walked the river I did see a few caddis coming off the water, so I suspect caddis dries should work well. 


Small Bridge

Best numbers of invertebrates on the river. Good showing of caseless caddis and olives. Plus a few smatterings of Heptageniids, stone fly and shrimp. While I was there I saw a member catch a five pound rainbow on a PTN.


Above the weir is now looking like a good invertebrate habitat with lots of caseless caddis to be found. I think this is a testament to the great work in removing the weir, as now this should be good habitat for wildlife generally. I met a member who told me he had caught a number of grayling above the weir on dry fly, so it's great to see these moving up the river. 


I also sampled between the stream and the bridge. This was looking better than previous years with caddis and olives showing. 


All in all, all looks good. 

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