June 2022

Comment on Mayfly Hatches and Catches

I am sorry this report is a little late but our head statistician (the Hon Sec) has been on holiday in Portugal. (Fortunately he was able to get to and from the UK as planned, unlike other holiday travellers!) I was particularly interested to compare the June results this season with those in 2021, and he has now given us the figures from your catch returns. On the face of it these compare unfavourably with last season: some 364 takeable brown trout were killed or returned, compared to 555 in June 2021 – a reduction of 35%. Undersized (wild) browns were also down by nearly a half – 122 this year compared to 220 last. But – and it is a big but – the recorded visits to the river were also down by 30% this year compared to 2021, so the numbers of fish caught per visit during June in both years were very similar (averaging between 3 and 4). Clearly the escape from lockdown last season was a crucial factor, encouraging many more of our members to fish, and indeed led to concerns in committee over the rod pressure during the Mayfly period. This now seems to have returned to an acceptable level.

That said, there was a marked difference in the pattern of hatches between the two seasons. This year the hatches started much earlier than usual, and were largely unpredictable – very localised, very variable in the time of day, and spread out over both May and June. Hence these typical catch return comments:

8 June: “Mayfly seems to be over”.

21 June: “Still a very healthy Mayfly hatch”

30 June: “Occasional Mayfly hatching”.

So it has been really a matter of luck and a cause for rejoicing if you actually encountered a hatch – in particular, if it was just starting. There really has not been an identifiable Duffers Fortnight, and some of our members were extremely successful during June in switching between imitations of the hatching Mayfly dun (Robjent’s Mohican pattern again coming in for praise), Gold Ribbed Hare’s Ear nymph and very small Shuttlecock emergers or F-flies. The ever-reliable Black Gnat also proved effective. The key as ever has been to find a feeding fish, to try to identify what it is taking, and then making a very cautious approach in the low water after the weed cut which has made fish very spooky and “picky”. Several days of downstream wind has not made the approach any easier either. But I hope you would agree that this month has actually produced some exceptionally interesting fly-fishing – both dry and nymph.

Grayling

As I have mentioned in previous reports, our catch return statistics do not give any real cause for concern about grayling, (over 300 were recorded in June, all of which were returned). But of course there has been a marked long-term decline since the days of Frank Sawyer in the 1960s and 70s, when these fish were so prolific that they were regarded as vermin and often knocked on the head. Not so nowadays thankfully, and I have recently corresponded with the Grayling Society to give our own views on this. I have pointed out that while the extensive restoration work on our fishery that has taken place annually since the late 1990s has undoubtedly benefited our wild brown trout population, this does not appear to have done the same for grayling. This is unsurprising, as the whole point of restoration work is to energise river flows in order to improve in-channel habitat by cleaning spawning gravels and encouraging the growth of ranunculus - which in turn generates the invertebrates on which our trout feed. So of course do grayling, but it is clear to me that in making our so-called “improvements” we have reduced the number and extent of the slower, deeper, more silted pools which are the preferred habitat of adult grayling. I believe our population of the bigger grayling (that is over 12”) has reduced as a result of restoration work. It can be argued that the successful recruitment of juveniles will “knock-on”  into the abundance of the adult population, but I am not convinced that we are holding these adults to the extent we would like to see. Although there is nothing we can do about this, we should all keep an eye on them – in particular we welcome comments in your catch returns on larger adults and any shoals you encounter.

Miscellaneous

A few small unrelated points:

  • I have a cap which was found on the river bank. Give me a ring if you have lost one.
  • Please do challenge and let me know of any poaching you encounter – at the moment it seems that Gunville hatch pool is the favoured site which I am afraid is a productive place for spinning.
  • It is good news that our water voles seem to be flourishing – do continue to report any sightings in the catch returns. I mention this again because there is a lot of concern nationally about their continued decline.

Finally – good luck this month. July is not the easiest time on our fishery but year after year it is so obvious that the very best of the fishing at the moment is in late evening, particularly in hot weather.

 

Martin Browne

Tel: 07768 354788